KR20220073740A - Interaction between reference picture resampling and video coding tools - Google Patents

Abstract

An exemplary method of video processing includes determining to use a coding tool based on a condition associated with a dimension of a portion of one of multiple reference pictures or a current picture to transform between a current picture of the video and a bitstream representation of the video. include The method also includes performing a transformation based on the determining step.

Description

Interaction between reference picture resampling and video coding tools

This patent document relates to video coding technology, apparatus and system.

Subject to corresponding patent laws and/or rules under the Paris Convention, this application is made to assert the priority and benefit of U.S. Provisional Patent Application No. 62/914,544, filed on October 13, 2019, in a timely manner. For all purposes under the law, the entire disclosure of this application is hereby incorporated by reference as a part of the disclosure of this application.

Efforts are currently underway to improve the performance of current video codec technologies to provide video coding and decoding schemes that either provide better compression ratios or allow for lower complexity or parallel implementations. Industry experts have recently proposed several new video coding tools, and testing to confirm their effectiveness is currently underway.

Apparatus, systems and methods related to digital video coding, particularly management of motion vectors, are described. The described method may be applied to existing video coding standards (eg, High Efficiency Video Coding (HEVC) or Versatile Video Coding) and future video coding standards or video codecs.

In one representative aspect, the disclosed technology may be used to provide a method for video processing. The method includes performing a transform between a current video block and a coded representation of the current video block, wherein if a resolution and/or size of a reference picture is different from the resolution and/or size of the current video block during transform, the current The same interpolation filter is applied to adjacent or non-adjacent sample groups predicted using video blocks.

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method comprises performing a transform between a current video block and a coded representation of the current video block, wherein during transforming, if a resolution and/or size of a reference picture is different from a resolution and/or size of the current video block, Here, a block predicted using the current video block is allowed to use only integer-valued motion information related to the current block.

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method comprises performing a transform between a current video block and a coded representation of the current video block, wherein during transforming, if a resolution and/or size of a reference picture is different from a resolution and/or size of the current video block, An interpolation filter is applied to derive a predicted block using the current video block, and the interpolation filter is selected based on the rule.

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method comprises performing a transform between a current video block and a coded representation of the current video block, wherein during transforming, if a resolution and/or size of a reference picture is different from a resolution and/or size of the current video block, Optionally, a deblocking filter is applied, and the strength of the deblocking filter is set according to a rule related to the size and/or resolution of the reference picture relative to the resolution and/or size of the current video block.

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method includes performing a transform between a current video block and a coded representation of the current video block, wherein during the transform, a reference picture of the current video block is resampled according to a rule based on a dimension of the current video block. .

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method includes performing a transform between a current video block and a coded representation of the current video block, wherein during the transform, use of a coding tool for the current video block determines the resolution/size of the current video block. It is selectively activated or deactivated according to the resolution/size of the reference picture of the block.

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method includes performing a transform between multiple video blocks and a coded representation of the multiple video blocks, wherein during transform, a first conformance window for a first video block and a second video block A second conformance window is defined for which the ratio of the width and/or height of the first conformance window to the second conformance window is at least according to a rule based on the conformance bitstream.

In another representative aspect, the disclosed technology may be used to provide other video processing methods. The method includes performing a transform between multiple video blocks and a coded representation of the multiple video blocks, wherein during transform, a first conformance window for a first video block and a second video block A second conformance window is defined for which the ratio of the width and/or height of the first conformance window to the second conformance window is at least according to a rule based on the conformance bitstream.

Also disclosed in a representative aspect is an apparatus for a video system comprising a processor and a non-transitory memory having instructions. The instructions, when executed by the processor, cause the processor to implement any one or more of the disclosed methods.

In one representative aspect, a video decoding apparatus comprising a processor configured to implement the methods recited herein is disclosed.

In one representative aspect, a video encoding apparatus comprising a processor configured to implement the methods recited herein is disclosed.

A computer program stored on a non-transitory computer-readable medium, comprising program code for performing any one of the methods of solutions F1 to F15.

These and other aspects and features of the disclosed technology are set forth in greater detail in the drawings, description and claims.

1 shows an example of a sub-block motion vector (VSB) and a motion vector difference.
2 shows an example of a 16x16 video block divided into 16 4x4 regions.
3A shows an example of a specific location within a sample.
3B shows another example of a specific location within a sample.
3C shows another example of a specific location within a sample.
4A shows an example of the position of the current sample and its reference sample.
4B shows another example of the position of the current sample and its reference sample.
5 is a block diagram of an example of a hardware platform for implementing the visual media decoding or visual media encoding technique described in this document.
6 shows a flow diagram of an example method for video coding.
7 shows an example of decoder-side motion vector refinement.
8 shows an example flow of cascading DMVR and BDOF processes in VTM5.0. DMVR SAD operation and BDOF SAD operation are different and are not shared.
9 is a block diagram of an example video processing system in which the disclosed techniques may be implemented.
10 is a block diagram illustrating an example video coding system.
11 is a block diagram illustrating an encoder in accordance with some embodiments of the present disclosure.
12 is a block diagram illustrating a decoder in accordance with some embodiments of the present disclosure.
13 is a flowchart representation of a video processing method according to the present technology.
14 is a flowchart representation of another method of video processing according to the present technology.
15 is a flowchart representation of another method of video processing in accordance with the present technology.

One. Video Coding in HEVC/H.265

Video coding standards have evolved primarily through the development of the well-known ITU-T and ISO/IEC standards. ITU-T produced H.261 and H.263, ISO/IEC produced MPEG-1 and MPEG-4 visuals, both organizations produced H.262/MPEG-2 video and H.264/MPEG-4 Co-authored the Advanced Video Coding (AVC) and H.265/HEVC standards. Since H.262, the video coding standard is based on a hybrid video coding scheme in which temporal prediction and transform coding are used. To explore future video coding technologies beyond HEVC, the Joint Video Exploration Team (JVET) was jointly established by VCEG and MPEG in 2015. Since then, many new methods have been adopted by JVET and applied to reference software named Joint Exploration Model (JEM). In April 2018, the Joint Video Expert Team (JVET) between VCEG (Q6/16) and ISO/IEC JTC1 SC29/WG11 (MPEG) announced a goal of 50% bitrate reduction compared to HEVC. It was made for working with the VVC standard.

2. summary

2.1. Adaptive Resolution Change (ARC)

AVC and HEVC cannot change resolution without introducing IDR or Intra Random Access Point (IRAP) pictures; This capability may be referred to as Adaptive Resolution Change (ARC). There are use cases or application scenarios where you can benefit from ARC features, including:

- Speed adjustment of video calls and conferences: In order to adapt the coded video to changing network conditions, when the available bandwidth becomes low as the network conditions deteriorate, the encoder can adapt by encoding a picture of a smaller resolution. Currently, picture resolution change can only be performed after IRAP pictures; This has some problems. An IRAP picture of reasonable quality is much larger than an inter-coded picture, and therefore decoding is more complex: this takes time and resources. This is a problem when the decoder requests a resolution change for loading reasons. It can also break low-latency buffer conditions and force audio resynchronization, and at least temporarily increase the end-to-end delay of the stream. This may result in a bad user experience.

- Change presenter active in a multiway video conference: - Change active speaker in a multiway video conference: In a multiway video conference, it is common for the current speaker to be displayed in a larger video size than the video of the rest of the meeting participants. If the current speaker changes, the picture resolution of each participant may also need to be adjusted. The need for the ARC function becomes even more important when these active speaker changes occur frequently.

- Quick Start of Streaming: For streaming applications, it is common for the application to buffer up to a certain length of the decoded picture before starting display. Starting the bitstream at a smaller resolution allows the application to have enough pictures to display in the buffer faster.

Adaptive Stream Conversion of Streaming: The Dynamic Adaptive Streaming over HTTP (DASH) specification includes a feature called @mediaStreamStructureId. This enables switching between different representations in open GOP random access points with non-decodable leading pictures, eg CRA pictures with associated RASL pictures in HEVC. If two different representations of the same video have different bitrates but the same spatial resolution while having the same value of @mediaStreamStructureId, a transition between the two representations can be performed in a CRA picture with an associated RASL picture, and the transition CRA picture (switching-at CRA picture) can be decoded with acceptable quality, enabling smooth switching. With ARC, you can also switch between DASH representations with different spatial resolutions using the @mediaStreamStructureId function.

ARC is also called dynamic resolution conversion.

ARC may be considered as a special case of Reference Picture Resampling (RPR), such as H.263 Annex P.

2.2. Reference picture resampling of H.263 Annex P

This mode describes an algorithm that warps a reference picture before using it for prediction. It can be useful for resampling a reference picture that has a different source format than the predicted picture. In addition, the shape, size, and position of the reference picture may be warped and used for global motion estimation or rotational motion estimation. The syntax includes the warping parameters to use and the resampling algorithm. The simplest operation level of the reference picture resampling mode is an implicit element of 4 resampling because only the FIR filter needs to be applied to the upsampling and downsampling processes. In this case, an additional signaling overhead is not required because the use is understood when the size of the new picture (indicated in the picture header) is different from that of the previous picture.

2.3. VVC's conformance window

The conformance window of VVC defines a rectangle. Samples inside the fit window belong to the image of interest. Samples outside the conformance window may be discarded on output.

When the conformance window is applied, the scaling ratio of the RPR is derived based on the conformance window.

Picture parameter set RBSP syntax.

pic_width_in_luma_samples specifies the width of each decoded picture referring to the PPS in the luma sample unit. pic_width_in_luma_samples must not be 0, must be an integer multiple of Max(8, MinCbSizeY), and must be less than or equal to pic_width_max_in_luma_samples.

When subpics_present_flag is equal to 1, the value of pic_width_in_luma_samples shall be equal to pic_width_max_in_luma_samples.

pic_height_in_luma_samples specifies the height of each decoded picture referring to the PPS in the luma sample unit. pic_height_in_luma_samples must be non-zero, must be an integer multiple of Max( 8, MinCbSizeY ), and must be less than or equal to pic_height_max_in_luma_samples.

When subpics_present_flag is equal to 1, the value of pic_height_in_luma_samples shall be equal to pic_height_max_in_luma_samples.

Let refPicWidthInLumaSamples and refPicHeightInLumaSamples be pic_width_in_luma_samples and pic_height_in_luma_samples of the reference picture of the current picture referring to this PPS, respectively. A bitstream conformance requirement where all of the following conditions are met:

- - pic_width_in_luma_samples * 2 must be greater than or equal to refPicWidthInLumaSamples.

- - pic_height_in_luma_samples * 2 must be greater than or equal to refPicHeightInLumaSamples.

- - pic_width_in_luma_samples must be less than or equal to refPicWidthInLumaSamples * 8.

- - pic_height_in_luma_samples must be less than or equal to refPicHeightInLumaSamples * 8.

conformance_window_flag equal to 1 indicates that the conformance cropping window offset parameter in SPS follows. conformance_window_flag equal to 0 indicates that the conformance cropping window offset parameter does not exist.

conf_win_left_offset, conf_win_right_offset, conf_win_top_offset and conf_win_bottom_offset specify picture samples of CVS output in the decoding process in terms of the rectangular area specified in picture coordinates for output. When conformance_window_flag is equal to 0, the values of conf_win_left_offset, conf_win_right_offset, conf_win_top_offset, and conf_win_bottom_offset are inferred to be equal to 0.

적합성 크로핑 윈도우는 SubWidthC　*　conf_win_left_offset to pic_width_in_luma_samples　-　(　SubWidthC　*　conf_win_right_offset　+　1　의 수평 픽처 좌표 및 SubHeightC　*　conf_win_top_offset to pic_height_in_luma_samples　-　(　SubHeightC　*　conf_win_bottom_offset　+　1　)의 수직 픽처 좌표가 포함되는 좌표를 갖는 루마 샘플을 포함한다 .

The value of SubWidthC * ( conf_win_left_offset + conf_win_right_offset ) must be less than pic_width_in_luma_samples, and the value of SubHeightC * ( conf_win_top_offset + conf_win_bottom_offset ) must be less than pic_height_in_luma_samples.

The PicOutputWidthL and PicOutputHeightL variables are derived as follows:

PicOutputWidthL = pic_width_in_luma_samples - (7-43)

SubWidthC * ( conf_win_right_offset + conf_win_left_offset )

PicOutputHeightL = pic_height_in_pic_size_units - (7-44) SubHeightC * ( conf_win_bottom_offset + conf_win_top_offset )

When ChromaArrayType is non-zero, the corresponding specified samples of both chroma arrays are samples with picture coordinates ( x / SubWidthC, y / SubHeightC ), where ( x, y ) is the picture coordinate of the specified luma sample.

Note - The conformance cropping window offset parameter only applies to outputs. All internal decoding processes are applied to the uncropped picture size.

Assume that ppsA and ppsB are any two PPSs referencing the same SPS. When ppsA and ppsB have the same values of pic_width_in_luma_samples and pic_height_in_luma_samples, respectively, it is a requirement of bitstream that ppsA and ppsB must have the same conformance values of conf_win_left_offset, conf_win_right_offset, conf_win_right_offset, _offset_win,_conf, respectively.

2.4. Reference Picture Resampling (RPR)

In some embodiments, ARC is also known as reference picture resampling (RPR). In some implementations of RPR, TMVP is disabled when the resolution of the collocated picture is different from the current picture. In addition, when the resolution of the reference picture is different from the current picture, Bi-Directional Optical Flow (BDOF) and Decoder-side Motion Vector Refinement (DMVR) are deactivated.

To handle normal MC when the reference picture has a different resolution than the current picture, the interpolation section is defined as follows:

8.5.6.3 Fractional sample interpolation process

8.5.6.3.1 General

Inputs to this process are:

- Luma position (xSb, ySb) designating the upper left sample of the current coding subblock based on the upper left luma sample of the current picture,

- Variable sbWidth specifying the width of the current coding subblock,

- Variable sbHeight that specifies the height of the current coding subblock,

- motion vector offset mvOffset,

- stylish motion vector refMvLX,

- selected reference picture sample array refPicLX,

- half-sample interpolation filter index hpelIfIdx,

- bidirectional optical flow flag bdofFlag,

- Variable cIdx designating the color component index of the current block.

The output of this process is:

- (sbWidth　+　brdExtSize)x(sbHeight　+　brdExtSize) array predSamplesLX of prediction

The prediction block boundary extension size brdExtSize is derived as follows:

brdExtSize = (　bdofFlag |　| (　inter_affine_flag[　xSb　][　ySb　] && sps_affine_prof_enabled_flag　)　) ? 2: 0 (8-752)

The variable fRefWidth is set equal to PicOutputWidthL of the reference picture in luma samples.

The variable fRefHeight is set equal to PicOutputHeightL of the reference picture in the luma sample.

It is set equal to the motion vector mvLX (refMvLX - mvOffset).

- If cIdx is 0, the following applies.

- The scaling factor and fixed-point representation are defined as follows.

hori_scale_fp =((fRefWidth << 14) +(PicOutputWidthL >> 1))/PicOutputWidthL (8-753)

vert_scale_fp =((fRefHeight << 14) +(PicOutputHeightL >> 1))/PicOutputHeightL (8-754)

- (xIntL, yIntL) is the luma position given in whole sample units, and (xFracL, yFracL) is the offset given in 1/16 sample units. These variables are used only in this section to specify the fractional sample location inside the reference sample array refPicLX.

- The upper left coordinate of the boundary block for reference sample padding (xSbIntL, ySbIntL) is set equal to (xSb +(mvLX [0] >> 4), ySb +(mvLX [1] >> 4)).

- for each luma sample position in the predicted luma sample array predSamplesLX (x _L = 0..sbWidth - 1 + brdExtSize, y _L = 0..sbHeight - 1 + brdExtSize), the corresponding predicted luma sample value predSamplesLX [x _L ] [y _L ] is derived as:

- (refxSb _L , refySb _L ) and (refx _L , refy _L ) are the luma positions pointed to by motion vectors (refMvLX [0], refMvLX [1]) specified in 1/16-sample units. The variables refxSb _L , refx _L , refySb _L and refy _L are derived as follows:

refxSb _L = ( ( xSb << 4 ) + refMvLX[ 0 ] ) * hori_scale_fp (8-755)

refx _L =((Sign(refxSb) *((Abs(refxSb) + 128) >> 8)

+ x _L *((hori_scale_fp + 8) >> 4)) + 32) >> 6 (8-756)

refySb _L = ( ( ySb << 4 ) + refMvLX[ 1 ] ) * vert_scale_fp (8-757)

refyL =((Sign(refySb) *((Abs(refySb) + 128) >> 8) + yL *

( ( vert_scale_fp + 8 ) >> 4 ) ) + 32 ) >> 6 (8-758)

- xInt _L , yInt _L , xFrac _L and yFrac _L variables are derived as follows:

xInt _L = refx _L >> 4 (8-759)

yInt _L = refy _L >> 4 (8-760)

xFrac _L = refx _L & 15 (8-761)

yFrac _L = refy _L & 15 (8-762)

- If bdofFlag is equal to TRUE ( sps_affine_prof_enabled_flag is TRUE and inter_affine_flag[ xSb ][ ySb ] is equal to TRUE, and one or more of the following conditions are true, the predicted luma sample value predSamplesLX[ x _L ][ y _L ] ( xIntL + ( xFrac _L >> 3 ) - 1), yInt _L + ( yFrac _L >> 3 ) - 1 ) and refPicLX as inputs, the luma integer sample specified in section 8.5.6.3.3 Derived by invoking the import process.

- x _L is equal to zero.

- x _L is equal to sbWidth + 1.

- y _L is equal to 0.

- y _L is equal to sbHeight + 1.

- Otherwise, the predicted luma sample values predSamplesLX[xL][yL] are (xIntL-(brdExtSize > 0? 1: 0), yIntL-(brdExtSize > 0? 1: 0)), (xFracL, yFracL), (xSbInt) _L , ySbInt _L ), refPicLX, hpelIfIdx, sbWidth, sbHeight, and (xSb, ySb) are derived by invoking the luma sample 8-tap interpolation filtering process specified in section 8.5.6.3.2 as input.

- Otherwise (cIdx is not 0), the following applies:

Let (xIntC, yIntC) be the chroma position given in whole sample units and (xFracC, yFracC) be the offset given in 1/32 sample units. These variables are used only in this section to specify common fractional sample locations within the reference sample array refPicLX.

- The upper-left coordinates of the bounding block for reference sample padding (xSbIntC, ySbIntC) are ((xSb/SubWidthC) +(mvLX [0] >> 5), (ySb/SubHeightC) +(mvLX [1 ] >> 5) ) is set the same as

- for each chroma sample position (xC = 0..sbWidth - 1, yC = 0 .. sbHeight - 1) in the predicted chroma sample array predSamplesLX, the corresponding predicted chroma sample value predSamplesLX [xC] [yC] is is derived:

- Let (refxSb _C , refySb _C ) and (refx _C , refy _C ) be the chroma positions pointed to by the motion vectors (mvLX [0], mvLX [1]) given in 1/32 sample units. The variables refxSb _C , refySb _C , refx _C and refy _C are derived as follows:

refxSb _C = ( ( xSb / SubWidthC << 5 ) + mvLX[ 0 ] ) * hori_scale_fp (8-763)

refx _C =((Sign(refxSb _C ) *((Abs(refxSb _C ) + 256) >> 9)

+ xC * ( ( hori_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-764)

refySb _C = ( ( ySb / SubHeightC << 5 ) + mvLX[ 1 ] ) * vert_scale_fp (8-765)

refy _C =((Sign(refySb _C ) *((Abs(refySb _C ) + 256) >> 9)

+ yC* ( ( vert_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-766)

- the variables xInt _C , yInt _C , xFrac _C and yFrac _c are derived as follows:

xInt _C = refx _C >> 5 (8-767)

yInt _C = refy _C >> 5 (8-768)

xFrac _C = refy _C & 31 (8-769)

yFrac _C = refy _C & 31 (8-770)

- The predicted sample values predSamplesLX[xC][yC] are derived by calling the process specified in 8.5.6.3.4 with (xIntC, yIntC), (xFracC, yFracC), (xSbIntC, ySbIntC), sbWidth, sbHeight, and refPicLX as inputs. do:

8.5.6.3.2 Luma Sample Interpolation Filtering Process

Inputs to this process are:

- Luma position of the entire sample unit (xInt _L , yInt _L )

- luma position of fractional sample units (xFrac _L , yFrac _L ),

- The luma position of the entire sample unit (xSbInt _L , ySbInt _L ) that specifies the upper-left sample of the boundary block for reference sample padding based on the upper-left luma sample of the reference picture,

- luma reference sample array refPicLX _L ,

- half-sample interpolation filter index hpelIfIdx,

- Variable sbWidth that specifies the width of the current subblock,

- Variable sbHeight that specifies the height of the current subblock,

- Luma position (xSb, ySb) that specifies the upper-left sample of the current subblock relative to the upper-left luma sample of the current picture;

The output of this process is the predicted luma sample value predSampleLX _L .

The shift1, shift2 and shift3 variables are derived as follows:

- Variable shift1 is set equal to Min(4, BitDepth _Y - 8), variable shift2 is set equal to 6, and variable shift3 is set equal to Max(2, 14 - BitDepth _Y ).

- The variable picW is set equal to pic_width_in_luma_samples, and the variable picH is set equal to pic_height_in_luma_samples.

The luma interpolation filter coefficients f _L [p] for each 1/16 fractional sample position p, such as xFrac _L or yFrac _L , are derived as follows:

- If MotionModelIdc [xSb] [ySb] is greater than 0 and both sbWidth and sbHeight are 4, the luma interpolation filter coefficient f _L [p] is specified in Table 2.

- Otherwise, the luma interpolation filter coefficients f _L [p] are specified in Table 1 according to hpelIfIdx.

The luma position of the whole sample unit (xInt _i , yInt _i ) is derived as follows for i = 0..7:

- If subpic_processor_as_pic_flag [SubPicIdx] is equal to 1, the following applies:

xInt _i = Clip3( SubPicLeftBoundaryPos, SubPicRightBoundaryPos, xInt _L + i - 3 ) (8-771)

yInt _i = Clip3( SubPicTopBoundaryPos, SubPicBotBoundaryPos, yInt _L + i - 3 ) (8-772)

- Otherwise (subpic_treat_as_pic_flag [SubPicIdx] equals 0), the following applies:

xInt _i = Clip3( 0, picW - 1, sps_ref_wraparound_enabled_flag ? ClipH( ( sps_ref_wraparound_offset_minus1 + 1 ) * MinCbSizeY, picW, xInt _L + i - 3 ) : (8-773)

xInt _L + i - 3)

yInt _i = Clip3(0, picH - 1, yInt _L + i - 3) (8-774)

The luma position of the whole sample unit is further modified as follows for i = 0..7:

xInt _i = Clip3(xSbInt _L - 3, xSbInt _L + sbWidth + 4, xInt _i ) (8-775)

yInt _i = Clip3(ySbInt _L - 3, ySbInt _L + sbHeight + 4, yInt _i ) (8-776)

The predicted luma sample value predSampleLX _L is derived as follows:

- If xFrac _L and yFrac _L are both 0, the value of predSampleLX _L is derived as follows:

predSampleLX _L = refPicLX _L [ xInt ₃ ][ yInt ₃ ] << shift3 (8-777)

- Otherwise, if xFrac _L is not 0 and yFrac _L is 0, the value of predSampleLX _L is derived as follows:

>>　　shift1 (8-778)predSampleLX _L =

>> shift1 (8-778)

- Otherwise, if xFrac _L is 0 and yFrac _L is non-zero, the value of predSampleLX _L is derived as follows:

>> shift1 (8-779)predSampleLX _L =

>> shift1 (8-779)

- Otherwise, if xFrac _L is non-zero and yFrac _L is non-zero, the value of predSampleLX _L is derived as follows:

- the sample array temp[n] with n = 0..7 is derived as follows:

　　>>　　shift1 (8-780)temp[ n ] =

>> shift1 (8-780)

- The predicted luma sample value predSampleLXL is derived as follows:

　>>　　shift2 (8-781)predSampleLX _L =

>> shift2 (8-781)

Specification of luma interpolation filter coefficients f _L [p] for each 1/16 fractional sample position p. Fractional sample position p interpolation filter coefficients f _L [p][0] f _L [p][1] f _L [p][2] f _L [p][3] f _L [p][4] f _L [p][5] f _L [p][6] f _L [p][7] One 0 One -3 63 4 -2 One 0 2 -One 2 -5 62 8 -3 One 0 3 -One 3 -8 60 13 -4 One 0 4 -One 4 -10 58 17 -5 One 0 5 -One 4 -11 52 26 -8 3 -One 6 -One 3 -9 47 31 -10 4 -One 7 -One 4 -11 45 34 -10 4 -One 8 (hpelIfIdx　=　=　0) -One 4 -11 40 40 -11 4 -One 8 (hpelIfIdx　=　=　1) 0 3 9 20 20 9 3 0 9 -One 4 -10 34 45 -11 4 -One 10 -One 4 -10 31 47 -9 3 -One 11 -One 3 -8 26 52 -11 4 -One 12 0 One -5 17 58 -10 4 -One 13 0 One -4 13 60 -8 3 -One 14 0 One -3 8 62 -5 2 -One 15 0 One -2 4 63 -3 One 0

Specification of luma interpolation filter coefficients f _L [p] for each 1/16th fractional sample position p for the affine motion mode. Fractional sample position p interpolation filter coefficients f _L [p][0] f _L [p][1] f _L [p][2] f _L [p][3] f _L [p][4] f _L [p][5] f _L [p][6] f _L [p][7] One 0 One -3 63 4 -2 One 0 2 0 One -5 62 8 -3 One 0 3 0 2 -8 60 13 -4 One 0 4 0 3 -10 58 17 -5 One 0 5 0 3 -11 52 26 -8 2 0 6 0 2 -9 47 31 -10 3 0 7 0 3 -11 45 34 -10 3 0 8 0 3 -11 40 40 -11 3 0 9 0 3 -10 34 45 -11 3 0 10 0 3 -10 31 47 -9 2 0 11 0 2 -8 26 52 -11 3 0 12 0 One -5 17 58 -10 3 0 13 0 One -4 13 60 -8 2 0 14 0 One -3 8 62 -5 One 0 15 0 One -2 4 63 -3 One 0

8.5.6.3.3 Luma integer sample fetching process

Inputs to this process are:

- Luma position of the entire sample unit (xInt _L , yInt _L )

- luma reference sample array refPicLX _L ,

The output of this process is the predicted luma sample value predSampleLX _L .

The variable shift is set equal to Max(2, 14 - BitDepth _Y ).

The variable picW is set equal to pic_width_in_luma_samples, and the variable picH is set equal to pic_height_in_luma_samples.

The luma position of the entire sample unit (xInt, yInt) is derived as follows:

xInt = Clip3(　0, picW　-　1, sps_ref_wraparound_enabled_flag ? (8-782)

ClipH( ( sps_ref_wraparound_offset_minus1 + 1 ) * MinCbSizeY, picW, xInt _L ) : xInt _L )

yInt = Clip3( 0, picH - 1, yInt _L ) (8-783)

The predicted luma sample value predSampleLX _L is derived as follows:

predSampleLX _L = refPicLX _L [ xInt ][ yInt ] << shift3 (8-784)

8.5.6.3.4 Chroma Sample Interpolation Process

Inputs to this process are:

- the chroma position of the whole sample unit (xInt _C , yInt _C ),

- Chroma position of 1/32 fractional sample units (xFrac _C , yFrac _C ),

- the chroma position of the entire sample unit (xSbInt _C , ySbInt _C ) that specifies the upper-left sample of the boundary block for reference sample padding with respect to the upper-left chroma sample of the reference picture,

- Variable sbWidth that specifies the width of the current subblock,

- Variable sbHeight that specifies the height of the current subblock,

- Chroma Reference Sample Array refPicLX _C

The output of this process is the predicted chroma sample value predSampleLX _C .

The shift1, shift2 and shift3 variables are derived as follows:

- Variable shift1 is set equal to Min(4, BitDepth _C - 8), variable shift2 is set equal to 6, and shift3 variable is set equal to Max(2, 14 - BitDepth _C ).

- Variable picW _C is set equal to pic_width_in_luma_samples/SubWidth _C and variable picH _C is set equal to pic_height_in_luma_samples/SubHeightC.

The chroma interpolation filter coefficients f _C [p] for each 1/32 fractional sample position p, such as xFrac _C or yFrac _C , are specified in Table 3.

The variable xOffset is set equal to (sps_ref_wraparound_offset_minus1 + 1) * MinCbSizeY)/SubWidthC.

The chroma position of the whole sample unit (xInt _i , yInt _i ) is derived as follows for i = 0..3:

- If subpic_processor_as_pic_flag [SubPicIdx] is equal to 1, the following applies:

xInti = Clip3( SubPicLeftBoundaryPos / SubWidthC, SubPicRightBoundaryPos / SubWidthC, xIntL + i ) (8-785)

yInti = Clip3( SubPicTopBoundaryPos / SubHeightC, SubPicBotBoundaryPos / SubHeightC, yIntL + i ) (8-786)

- Otherwise (subpic_treat_as_pic_flag [SubPicIdx] equals 0), the following applies:

xInt _i = Clip3( 0, picW _C - 1, sps_ref_wraparound_enabled_flag ? ClipH( xOffset, picW _C , xInt _C + i - 1 ) : (8-787)

xInt _C + i - 1 )

yInt _i = Clip3( 0, picH _C - 1, yInt _C + i - 1 ) (8-788)

The chroma position of the whole sample unit ( xInt _i , yInt _i ) is further modified for i = 0..3 as follows:

xInt _i = Clip3( xSbIntC - 1, xSbIntC + sbWidth + 2, xInt _i ) (8-789)

yInt _i = Clip3( ySbIntC - 1, ySbIntC + sbHeight + 2, yInt _i ) (8-790)

The predicted chroma sample value predSampleLX _C is derived as follows:

- if xFrac _C and yFrac _C are both 0, the value of predSampleLX _C is derived as follows:

predSampleLX _C = refPicLX _C [ xInt ₁ ][ yInt ₁ ] << shift3 (8-791)

- Otherwise, if xFrac _C is not 0 and yFrac _C is 0, then the value of predSampleLX _C is derived as follows:

　　>>　　shift1 (8-792)predSampleLX _C =

>> shift1 (8-792)

- Otherwise, if xFracC is 0 and yFracC is non-zero, the value of predSampleLXC is derived as follows:

　　>>　　shift1 (8-793)predSampleLX _C =

>> shift1 (8-793)

- Otherwise, if xFracC is non-zero and yFracC is non-zero, the value of predSampleLXC is derived as follows:

The sample array temp[n] with n = 0..3 is derived as follows:

　　>>　　shift1 (8-794)temp[ n ] =

>> shift1 (8-794)

The predicted chroma sample value predSampleLX _C is derived as follows:

][　0　]　*　temp[　0　]　+predSampleLX _C =( f _C [

][ 0 ] * temp[ 0 ] +

　][　1　]　*　temp[　1　]　+f _C [

][ 1 ] * temp[ 1 ] +

　][　2　]　*　temp[　2　]　+ (8-795)f _C [

][ 2 ] * temp[ 2 ] + (8-795)

　][　3　]　*　temp[　3　]　)　>>　shift2f _C [

][ 3 ] * temp[ 3 ] ) >> shift2

Specification of the chroma interpolation filter coefficients f _C [p] for each 1/32 fractional sample position p Fractional sample position p Interpolation filter coefficients f _C [　p　][　0　] f _C [　p　][　1　] f _C [　p　][　2　] f _C [　p　][　3　] One -One 63 2 0 2 -2 62 4 0 3 -2 60 7 -One 4 -2 58 10 -2 5 -3 57 12 -2 6 -4 56 14 -2 7 -4 55 15 -2 8 -4 54 16 -2 9 -5 53 18 -2 10 -6 52 20 -2 11 -6 49 24 -3 12 -6 46 28 -4 13 -5 44 29 -4 14 -4 42 30 -4 15 -4 39 33 -4 16 -4 36 36 -4 17 -4 33 39 -4 18 -4 30 42 -4 19 -4 29 44 -5 20 -4 28 46 -6 21 -3 24 49 -6 22 -2 20 52 -6 23 -2 18 53 -5 24 -2 16 54 -4 25 -2 15 55 -4 26 -2 14 56 -4 27 -2 12 57 -3 28 -2 10 58 -2 29 -One 7 60 -2 30 0 4 62 -2 31 0 2 63 -One

2.5. Refined sub-block based affine motion compensated prediction

The techniques disclosed herein include a method of refining subblock based affine motion compensated prediction with optical flow. After subblock-based affine motion compensation is performed, the prediction samples are refined using optical flow (PROF) to add differences derived by an optical flow equation called prediction refinement. The proposed method can achieve inter prediction with pixel-level granularity without increasing memory access bandwidth.

To achieve the granularity of motion compensation, this contribution proposes a method to refine subblock-based affine motion that compensates prediction with optical flow. After subblock-based affine motion compensation is performed, the luma prediction sample is refined by adding the difference derived by the optical flow equation. The proposed PROF (predictive refinement for optical flow) is described in the following four steps.

Step 1) Sub-block-based affine motion compensation is performed to generate sub-block predictions.

Step 2) The spatial gradients g _x (i,j) and g _y (i,j) of sub-block prediction are computed at each sample position using a 3-tap filter [-1, 0, 1].

The subblock prediction is expanded by 1 pixel on each side for gradient computation. To reduce memory bandwidth and complexity, pixels with extended borders are copied from the nearest integer pixel location in the reference picture. Therefore, additional interpolation for the padding area can be avoided.

Step 3) Luma prediction refinement (denoted as ΔI) as calculated by the optical flow equation.

where delta MV (denoted as Δv(i,j)) is the pixel MV calculated for the sample position (i,j) expressed as v(i,j) and, as shown in Fig. 1, pixel (i,j) ) is the difference between the subblock MVs of the subblock to which it belongs. One.

Since the affine model parameters and the pixel position for the subblock center do not change from subblock to subblock, Δv(i,j) can be calculated for the first subblock and be reused for other subblocks of the same CU. can Let x and y be the horizontal and vertical offsets from the pixel position to the center of the subblock, Δv(i,j) can be derived by the following equation:

For the 4-parameter affine model

For a 6-parameter affine model

는 왼쪽 상단, 오른쪽 상단 및 왼쪽 하단 제어점 모션 벡터이고, w 및 h는 는 CU의 너비와 높이이다.here

are the upper-left, upper-right, and lower-left control point motion vectors, and w and h are the width and height of the CU.

Step 4) Finally, a luma prediction specification is added to the subblock prediction I(i,j). The final prediction I' is generated by the following equation:

Some details are explained below:

a) How to derive the gradient of PROF

In some embodiments, a gradient is calculated for each subblock (4Х4 subblock of VTM-4.0) for each reference list. For each subblock, the nearest integer sample of the reference block is fetched to pad the outer four-sided line of the sample.

It is assumed that the MV for the current subblock is (MVx, MVy). Then the fractional part (FracX, FracY)==(MVx&15, MVy&15) is calculated. The integer part is calculated as (IntX, IntY)==(MVx>>4, MVy>>4). offset(OffsetX, OffsetY) is derived as follows.

OffsetX = FracX > 7 ? 1: 0;

OffsetY = FracY > 7 ? 1: 0;

It is assumed that the left coordinate of the current subblock is (xCur, yCur) and the dimension of the current subblock is WxH. Then (xCor0, yCor0), (xCor1, yCor1), (xCor2, yCor2) and (xCor3, yCor3) are calculated as:

(xCor0, yCor0) = (xCur+IntX+OffsetX-1, yCur+IntY+OffsetY-1);

(xCor1, yCor1) = (xCur+IntX+OffsetX-1, yCur+IntY+OffsetY+H);

(xCor2, yCor2) = (xCur+IntX+OffsetX-1, yCur+IntY+OffsetY);

(xCor3, yCor3) = (xCur+IntX+OffsetX+W, yCur+IntY+OffsetY);

x=0..W-1, y=0. Assume that PredSample[x][y] with H-1 stores prediction samples for subblocks. Then the padding sample is derived as follows:

PredSample[x][-1] = (Ref (xCor0+x, yCor0) << Shift0) - Rounding, x=-1..W;

PredSample[x][H] = (Ref (xCor1+x, yCor1) << Shift0) - Rounding, x=-1..W;

PredSample[-1][-1][y] = (Ref (xCor2, yCor2+y) << Shift0) - Rounding, y=0.H-1;

PredSample[W][y] = (Ref (xCor3, yCor3+y) << Shift0) - Rounding, y=0..H-1;

Rec indicates a reference picture. Rounding is an integer equal to 2 ¹³ in the example PROF implementation. Shift0 = Max(2, (14 - BitDepth)):_PROF attempts to increase the precision of the gradient, unlike the BIO of VTM-4.0 where the gradient is output with the same precision as the input luma samples.

The gradient of PROF is calculated as follows:

Shift1 = Shift0-4.

gradientH [ x ][ y ] = (predSamples [ x + 1 ][y] - predSample [ x -1 ][ y] ) >> Shift1

gradientV [ x ][ y ] = (predSample[ x ][ y + 1 ] - predSample [ x ]][y - 1 ] ) >> Shift1

It should be noted that predSamples[x][y] retains precision after interpolation.

b) how to derive Δv for PROF

The derivation of Δv (denoted as dMvH [posX][posY][posY][posX][posX][posY] [posY] [posY] and posY= 0..H-1) can be described as follows

Assume that the dimension of the current block is cbWidth Х cbHeight, the number of control point motion vectors is numCpMv, and the control point motion vector is cpMVX[cpIdx] where cpIdx = 0.numCpMv - 1 and X is 0 or 1 representing two reference lists. do.

The variables log2CbW and log2CbH are derived as follows:

log2CbW = Log2( cbWidth )

log2CbH　=　Log2( cbHeight )

The variables mvScaleHor, mvScaleVer, dHorX and dVerX are derived as follows:

mvScaleHor　=　cpMvLX[　0　][　0　]　<<　7

mvScaleVer　=　cpMvLX[　0　][　1　]　<<　7

dHorX　=　(　cpMvLX[　1　][　0　]　-　cpMvLX[　0　][　0　]　)　<<　(　7　-log2CbW　)

dVerX　=　(　cpMvLX[　1　][　1　]　-　cpMvLX[　0　][　1　]　)　<<　(　7　-log2CbW　)

The variables dHorY and dVerY are derived as follows:

If numCpMv is equal to 3, then the following applies:

dHorY　=　(　cpMvLX[　2　][　0　]　-　cpMvLX[　0　][　0　]　)　<<　(　7　-log2CbH)

dVerY　=　(　cpMvLX[　2　][　1　]　-　cpMvLX[　0　][　1　]　)　<<　(　7　-log2CbH)

Otherwise (numCpMv equals 2), the following applies:

dHorY　=　-　dVerX

dVerY　=　dHorX

The variables qHorX, qVerX, qHorY and qVerY are derived as follows:

qHorX = dHorX << 2;

qVerX = dVerX << 2;

qHorY = dHorY << 2;

qVerY = dVerY << 2;

dMvH[0][0][0] and dMvV[0][0][0] are calculated as follows:

dMvH[0][0] = ((dHorX + dHorY) << 1) - ((qHorX + qHorY) << 1);

dMvV[0][0] = ((dVerX + dVerY) << 1) - ((qVerX + qVerY) << 1);

dMvH[xPos][0] and dMvV[xPos][0] for xPos from 1 to W-1 are derived as follows:

dMvH[xPos][0] = dMvH[xPos-1][0] + qHorX;

dMvV[xPos][0] = dMvV[xPos-1][0] + qVerX;

For yPos from 1 to H-1, the following applies:

dMvH[xPos][yPos] = dMvH[xPos][yPos-1] + qHorY with xPos=0..W-1

dMvV[xPos][yPos] = dMvV[xPos][yPos-1] + qVerY with xPos=0..W-1

Finally, dMvH[xPos][yPos][yPos][xPos][yPos] [yPos] posX = 0.W-1, posY=0..H-1 is shifted right as follows:

dMvH[xPos][yPos] = SatShift(dMvH[xPos][yPos], 7+2-1);

dMvV[xPos][yPos] = SatShift( dMvV[xPos][yPos], 7+2-1);

where SatShift(x, n) and shift(x, n) are defined as:

If SatShift(x,n) = (x + offset0)>>n, x>=0, then

= -((-x + offset1)>>n ), if x<

shift(x,, n)=(x+ offset0)>>n

In one example, offset0 and/or offset1 is set to (1<<n)>>1.

c) method of deriving ΔI for PROF

For a position (posX, posY) inside a subblock, the corresponding Δv(i,j) is denoted by (dMvH[posX][posY], dMvV[posX][posY]. The corresponding gradient is (gradientH[posX) ][posY], gradientV[posX][posY].

Then ΔI(posX, posY) is derived as

(dMvH[posX][posY], dMvV[posX][posY] is clipped to:

dMvH[posX][posY] = Clip3(-32768, 32767, dMvH[posX][posY]);

dMvV[posX][posY] = Clip3(-32768, 32767, dMvV[posX][posY]);

ΔI(posX, posY) = dMvH[posX][posY] Х gradientH[posX][posY] + dMvV[posX][posY] Х gradientV[posX][posY];

ΔI(posX, posY) = Shift(ΔI(posX, posY), 1+1+4);

ΔI(posX, posY) = Clip3(-(2 ¹³ -1), 2 ¹³ -1, ΔI(posX, posY));

How to Derive I' for PROF

If the current block is not coded with double prediction or weighted prediction

I'(posX, posY) = Shift((I(posX, posY) + ΔI(posX, posY)), Shift0),

I'(posX, posY) = ClipSample(I'(posX, posY)),

Here ClipSample clips the sample value to a valid output sample value. Then, I'(posX, posY) is output as a mutual prediction value.

Otherwise (the current block is coded with double prediction or weighted prediction) I'(posX, posY) is stored and used to generate inter prediction values according to other prediction values and/or weight values. I'(posX, posY) is stored and used to generate inter-prediction values according to other prediction values and/or weight values.

2.6. Example Slice header

2.7. Example of a sequence parameter set

2.8 Example Picture Parameter Set

2.9. Example Adaptive Parameter Set

2.10. Example Picture header

In some embodiments, the picture header is designed to have the following properties:

1. The temporal Id and the layer Id of the picture header NAL unit are the same as the temporal Id and the layer Id of the layer access unit including the picture header.

2. The picture header NAL unit must precede the NAL unit containing the first slice of the associated picture. This established the association between the picture header and the picture slice associated with the picture header without having to have the picture header Id signaled in the picture header and referenced from the slice header.

3. The picture header NAL unit must follow the picture level parameter set or higher level such as DPS, VPS, SPS, PPS, etc. This in turn requires that this parameter set is not repeated or exists within a picture or within an access unit.

4. The picture header includes information on the picture type of the linked picture. Picture types can be used to define (not a complete list):

a. The picture is an IDR picture.

b. The picture is a CRA picture

c. The picture is a GDR picture.

d. A picture is a picture other than IRAP and GDR and contains only i-slice.

e. A picture is a non-IRAP GDR picture and can contain only P and I-slices.

f. A picture is a non-IRAP, non-GDR picture and contains B-, P- and/or I-slice.

5. Move the signaling of the picture level syntax element in the slice header to the picture header.

6. Signal non-picture level syntax elements in slice headers that are generally the same for all slices of the same picture-in-picture header. When such a syntax element does not exist in the picture header, it may be signaled in the slice header.

In some implementations, the essential picture header concept is used to be transmitted once per picture as the first VCL NAL unit of the picture. It is also proposed to move the syntax element in the current slice header to this picture header. A syntax element that functionally only needs to be transmitted once per picture can be moved to the picture header instead of being transmitted multiple times for a given picture, e.g., a syntax element of a slice header is transmitted once per slice. Moving slice header syntax element constrained to be identical within a picture

The syntax element is already constrained to be the same in all slices of a picture. If this field is moved to the picture header and the signal is received only once per picture instead of once per slice, unnecessary redundant transmission of bits can be prevented without changing the function of these syntax elements.

1. Some implementations have the following semantic constraints:

If present, the slice header syntax elements slice_pic_parameter_set_id, non_reference_picture_flag, color_plane_id, slice_pic_order_cnt_lsb, recovery_poc_cnt, no_output_of_prior_pics_flag, pic_output_flag, and slice_temporal_mvp_enabled_flag in each slice header must be the same values of the slice header. Therefore, each of these syntax elements can be moved to the picture header to avoid unnecessary redundant bits.

Recovery_poc_cnt and no_output_of_prior_pics_flag are not moved to the picture header in this contribution. Since its existence in the slice header depends on the conditional check of the slice header nal_unit_type, it is recommended to study this syntax element when moving it to the picture header.

2. Some implementations have the following semantic constraints:

If present, the value of slice_lmcs_aps_id must be the same for all slices of a picture.

If present, the value of slice_scaling_list_aps_id must be the same for all slices of a picture. Therefore, each of these syntax elements can be moved to the picture header to avoid unnecessary redundant bits.

In some embodiments, syntax elements are not constrained to be the same in all slices of a picture. Because it is claimed that there is a complexity impact in handling the large number of syntax elements in any slice header, it is worthwhile to evaluate the expected use of these syntax elements to determine what can be moved into the picture header to simplify the overall VVC design.

1. To move to the picture header, the following syntax elements are proposed. There are currently no restrictions on having different values for different slices, but it is claimed that there is no or minimal coding loss and advantages over transmitting in every slice header because the expected usage changes at the picture level.

a. six_minus_max_num_merge_cand

b. five_minus_max_num_subblock_merge_cand

c. slice_fpel_mmvd_enabled_flag

d. slice_disable_bdof_dmvr_flag

e. max_num_merge_cand_minus_max_num_triangle_cand

f. slice_six_minus_max_num_ibc_merge_cand

2. To move to the picture header, the following syntax elements are proposed. There are currently no restrictions on having different values for different slices, but it is claimed that there is no or minimal coding loss and advantages over transmitting in every slice header because the expected usage changes at the picture level.

a. partition_constraints_override_flag

b. slice_log2_diff_min_qt_min_cb_luma

c. slice_max_mtt_hierarchy_depth_luma

d. slice_log2_diff_max_bt_min_qt_luma

e. slice_log2_diff_max_tt_min_qt_luma

f. slice_log2_diff_min_qt_min_cb_chroma

g. slice_max_mtt_hierarchy_depth_chroma

h. slice_log2_diff_max_bt_min_qt_chroma

i. slice_log2_diff_max_tt_min_qt_chroma

The conditional check "slice_type == I" associated with some of these syntax elements was removed as it moved to the picture header.

3. To move to the picture header, the following syntax elements are proposed. There are currently no restrictions on having different values for different slices, but it is claimed that there is no or minimal coding loss and advantages over transmitting in all slice headers because the expected usage changes at the picture level.

a. mvd_l1_zero_flag

The conditional check "slice_type == B" associated with some of these syntax elements was removed as it moved to the picture header.

4. To move to the picture header, the following syntax elements are proposed. There are currently no restrictions on having different values for different slices, but it is claimed that there is no or minimal coding loss and advantages over transmitting in all slice headers because the expected usage changes at the picture level.

a. dep_quant_enabled_flag

b. sign_data_hiding_enabled_flag

2.10.1 Syntax table example

7.3.2.8 Picture header RBSP syntax

2.11. DMVR Yes

Decoder-side Motion Vector Refinement (DMVR) is a bi-directional matching to derive the motion information of the current CU by finding the closest match between two blocks along the motion trajectory of the current CU in two different reference pictures. (lateral matching) (BM) is used. The BM method calculates the distortion between two candidate blocks of the reference picture list L0 and the list L1. As shown in FIG. 1 , the SAD between the red blocks is calculated based on each MV candidate around the initial MV. The MV candidate of the shortest SAD becomes a refined MV and is used to generate a bidirectional prediction signal. The cost function used in the matching process is the row subsampled SAD (sum of absolute differences). Example of Figure 7.

In VTM5.0, DMVR is adopted to improve the motion vector (MV) at the decoder for a CU (coding unit) when the CU is coded with normal merge/skip mode and bi-prediction, and one reference picture precedes the current picture. and another reference picture is after the current picture in display order, the temporal distance between the current picture and one reference picture is equal to the distance between the current picture and another reference picture, and bidirectional prediction by CU weighting (BCW) has the same weight. choose When DMVR is applied, one luma coding block (CB) is divided into several independently processed subblocks with a size of min(cbWidth,16)Хmin(cbHeight,16). DMVR refines the MV of each subblock by minimizing the SAD between the 1/2 subsampled 10-bit L0 and L1 prediction samples generated by bilinear interpolation. For each subblock, an integer ΔMV search around the initial MV (ie, the MV of the selected general merge/skip candidate) is first performed using SAD, and then fractional ΔMV derivation is performed to obtain the final MV.

BDOF refines the luma prediction samples for a CU when the CU is coded with bi-prediction, one reference picture is before the current picture, another reference picture is after the current picture in display order, and BCW selects the same weight. 8-tap interpolation is used to generate initial L0 and L1 prediction samples according to the input MV (eg, the final MV of the DMVR when activating the DMVR). Next, a two-level early termination process is performed. The first early termination is at the subblock level, the second early termination is at the 4Х4 block level, and is confirmed when the first early termination does not occur. At each level, the SAD between the fully sampled 14-bit L0 and L1 prediction samples of each subblock/4x4 block is computed first. If SAD is less than one threshold, BDOF is not applied to subblock/4x4 block. Otherwise, the BDOF parameters are derived and used to generate the final luma sample predictor for each 4x4 block. In BDOF, the subblock size is equal to DMVR, ie min(cbWidth,16)Хmin(cbHeight,16).

When the CU is coded in normal merge/skip mode, one reference picture is before the current picture and another reference picture is after the current picture in display order, and the temporal distance between the current picture and one reference picture is different from the current picture. If a weight equal to the temporal distance between pictures and BCW is selected, both DMVR and BDOF are applied. The flow of the cascaded DMVR and BDOF process is shown in FIG. 8 .

Figure 8 shows the cascading flow of DMVR and BDOF processes in VTM5.0. DMVR SAD operation and BDOF SAD operation are different and not shared.

In order to reduce delay and operation in this critical path, when both DMVR and BDOF are applied, the latest VVC working draft has been modified to reuse the subblock SAD calculated in DMVR for subblock early termination of BDOF.

The SAD calculation is defined as:

where two variables nSbW and nSbH specify the width and height of the current subblock, and two ( nSbW + 4 ) x ( nSbH + 4 ) arrays pL0 and pL1, and prediction Integer sample offset ( dX, dY ) of list L0.

In order to reduce the penalty for uncertainty of DMVR refinement, it is proposed to prefer the original MV during the DMVR process. The SAD between the reference blocks referred to by the initial (or so-called original) MV candidate is reduced by 1/4 of the SAD value. That is, when dX and dY are both 0 in the above expression, the sad value is modified as follows:

sad = sad - (　sad　>>　2　)

If the SAD value is less than the threshold (2*subblock width*subblock height), there is no need to perform BDOF anymore.

3. Disadvantages of existing implementations

DMVR and BIO do not contain the original signal while refining motion vectors, so it can code blocks with inaccurate motion information. Also, DMVR and BIO sometimes use fractional motion vectors after motion refinement, but screen video generally uses integer motion vectors, so the current motion information is not more accurate and coding performance is poor.

When applying RPR in VVC, RPR (ARC) may have the following problems:

1. Using RPR may result in different interpolation filters for adjacent samples in a block, which is undesirable in Single Instruction Multiple Data (SIMD) implementations.

2. The bounding region does not consider RPR.

3. It states "The conformance cropping window offset parameter applies only to the output. All internal decoding processes are applied to the uncropped picture size." However, these parameters may be used in the decoding process when RPR is applied.

4. When deriving the reference sample position, RPR only considers the ratio between the two fit windows. However, the difference in the upper-left offset between the two conformance windows must also be taken into account.

5. The ratio between the width/height of the reference picture and the width/height of the current picture is constrained in VVC. However, the ratio between the width/height of the compatibility window of the reference picture and the width/height of the compatibility window of the current picture is not constrained.

6. Not all syntax elements are properly processed in the picture header.

7. In current VVC, chroma blending weights for TPM, GEO prediction modes are derived regardless of the chroma sample position type of the video sequence. For example, in TPM/GEO, if chroma weights are derived from luma weights, it may be necessary to downsample the luma weights to match the sampling of the chroma signals. Chroma downsampling is generally applied assuming chroma sample position type 0, which is widely used in ITU-R BT.601 or ITU-R BT.709 containers. However, if other chroma sample position types are used, this may result in misalignment between the chroma samples and the downsampled luma samples, which may reduce coding performance.

8. SAD Calculation/SAD Threshold does not consider bit-depth impact. Thus, for higher bit depths (eg, 14 or 16 bit input sequences), the threshold for early termination may be too small.

9. For non-RPR, AMVR with 1/2-pel MV precision (ie alternative interpolation filter/switchable interpolation filter) is applied with 6-tap motion compensation filter, but in other cases (e.g. , 1/16-pel) applies 8-tap. However, in the case of RPR, the same interpolation filter is applied in all cases without considering the mv/mvd precision. Thus, signaling in the 1/2-pel case (alternative interpolation filter/switchable interpolation filter) is wasting bits.

10. Whether to allow the partition tree division decision is determined according to the coded picture resolution instead of the output picture resolution.

11. SMVD/MMVD without considering RPR case is applied. This method is based on the assumption that symmetric MVD is applied to two reference pictures. However, when the resolution of the output picture is different, this assumption is not true.

12. A pairwise merge candidate is generated by averaging two MVs from two merge candidates in the same reference picture list. However, when two reference pictures related to two merge candidates have different resolutions, averaging is meaningless.

4. Exemplary Techniques and Examples

The detailed descriptions listed below should be considered as examples for illustrating general concepts. These examples should not be construed in a narrow way. Also, these embodiments may be combined in any manner.

Methods to be described later may be applied to other decoder motion information derivation technologies in addition to DMVR and BIO to be described later.

The motion vector is denoted by (mv_x, mv_y), where mv_x is the horizontal component and mv_y is the vertical component.

In this disclosure, the resolution (or dimension, or width/height, or size) of a picture may mean the resolution (or dimension, or width/height, or size) of a coded/decoded picture, or coded/decoded It may refer to the resolution (or dimension, or width/height, or size) of the conformance window in the given picture. In one example, the resolution (or dimension, or width/height, or size) of a picture may refer to a parameter related to a reference picture resampling (RPR) process, such as a scaling window/phase offset window. In one example, the resolution (or dimension, or width/height, or size) of a picture is related to that associated with the output picture.

RPR motion compensation

1. When the resolution of the reference picture is different from that of the current picture, or the width and/or height of the reference picture is greater than that of the current picture, the predicted values for the sample group (at least two samples) of the current block are the same horizontal and/or vertical interpolation It can be created as a filter.

a. In one example, a group may include all samples in an area of a block.

i. For example, a block may be divided into non-overlapping S MxN rectangles. Each MxN rectangle is a group. In the example as shown in Figure 2, a 16x16 block can be divided into 16 4x4 rectangles, each being a group.

ii. For example, a row with N samples is a group. N is an integer not greater than the block width. In one example, N is 4 or 8 or a block width.

iii. For example, a column with N samples is a group. N is an integer not greater than the block height. In one example, N is 4 or 8 or block height.

iv. M and/or N may be derived or signaled on the fly, such as based on predefined or block dimension/coded information.

b. In one example, samples in a group may have the same MV (denoted as shared MV).

c. In one example, samples in a group may have MVs with the same horizontal component (represented as a shared horizontal component).

d. In one example, samples in a group may have MVs with the same vertical component (represented as a shared vertical component).

e. In one example, the samples in the group may have MVs that have the same fractional portion of the horizontal component (represented by the shared fractional horizontal component).

i. For example, assuming that the MV of the first sample is (MV1x, MV1y) and the MV of the second sample is (MV2x, MV2y), MV1x & (2 ^M -1) is equal to MV2x & (2 ^M -1) must be satisfied, where M represents the MV precision. For example, M=4.

f. In one example, the samples in the group may have MVs that have the same fractional portion of the vertical component (represented by the shared fractional vertical component).

i. For example, assuming that the MV of the first sample is (MV1x, MV1y) and the MV of the second sample is (MV2x, MV2y), MV1y & (2 ^M -1) is equal to MV2y & (2 ^M -1) must be satisfied, where M represents the MV precision. For example, M=4.

g. In one example, for a sample in a group to be predicted, a motion vector denoted by MV _b may be first derived according to the resolution of the current picture and the reference picture (eg, 8.5.6.3.1 of JVET-O2001-v14). derived from (refx _L , refy _L )). Then, MV _b can be further modified (e.g. rounded/truncated/clipped) by MV' to meet the same requirements as above, and MV' is used to derive the predicted sample for the sample. do.

i. In one example, MV' has an integer part equal to MV _b , and the fractional part of MV' is set to a shared fractional horizontal and/or vertical component.

ii. In one example, MV' is set to the closest to MV _b with a shared fractional horizontal and/or vertical component.

h. A shared motion vector (and/or a shared horizontal component and/or a shared vertical component and/or a shared fractional vertical component and/or a shared fractional vertical component) is a motion vector (and/or a horizontal component and/or a vertical component) of a particular sample within a group. and/or a fractional vertical component and/or a fractional vertical component).

i. For example, a particular sample may be at the edge of a group of rectangles such as “A”, “B’, “C” and “D” shown in FIG. 3A .

ii. For example, a particular sample may be centered in a group of rectangles such as “E”, “F’, “G”, “H” shown in FIG. 3A .

iii. For example, a particular sample may be at the end of a group in the form of rows or columns, such as “A” and “D” shown in FIGS. 3B and 3C .

iv. For example, a particular sample may be in the middle of a row or column group such as “B” and “C” shown in FIGS. 3B and 3C .

v. In one example, the motion vector of a particular sample may be the MV _b mentioned in item g.

i. A shared motion vector (and/or a shared horizontal component and/or a shared vertical component and/or a shared fractional vertical component and/or a shared fractional vertical component) is a motion vector (and/or or a horizontal component and/or a vertical component and/or a fractional vertical component and/or a fractional vertical component).

i. In one example, the virtual sample is not in the group but is in a region containing all samples in the group.

One) Alternatively, the virtual sample is located outside the region containing all samples in the group, eg next to the lower right position of the region.

ii. In one example, the MV of the virtual sample is derived in the same way as the real sample, but with a different location.

iii. “V” in FIGS. 3A-3C represents three examples of hypothetical samples.

j. A shared MV (and/or a shared horizontal component and/or a shared vertical component and/or a shared fractional vertical component and/or a shared fractional vertical component) is a function of the MVs of multiple samples and/or virtual samples (and/or a horizontal component and/or a or a vertical component and/or a fractional vertical component and/or a fractional vertical component).

i. For example, a shared MV (and/or a shared horizontal component and/or a shared vertical component and/or a shared fractional vertical component and/or a shared fractional vertical component) is a group or sample "E", "F" of FIG. 3A , “G”, “H”, or sample “A”, “B”, “C”, “D” in FIG. 3A , sample “A”, “D” in FIG. 3A, or sample “B” in FIG. 3A , "C", sample "A", "D" in FIG. 3B, sample "B", "C" in FIG. 3B, or sample "A", "D" in FIG. 3C, or sample "A", "D" Mean of the MVs of all or some samples (and/or a horizontal component and/or a vertical component and/or a fractional vertical component and/or a fractional vertical component).

2. The interpolation filter used in the motion compensation process to derive the predictive block of the current block can be selected depending on whether the resolution of the reference picture is different from the current picture or whether the width and/or height of the reference picture is greater than the resolution of the current picture. suggest that there is

a. In one example, the decoded motion vector for a sample to be predicted is rounded to an integer MV before being used.

b. In one example, the decoded motion vector for the sample to be predicted is rounded to the nearest integer MV to the decoded motion vector.

c. In one example, the decoded motion vector for the sample to be predicted is rounded to the nearest integer MV to the decoded motion vector in the horizontal direction.

d. In one example, the decoded motion vector for the sample to be predicted is rounded to the nearest integer MV to the decoded motion vector in the vertical direction.

3. The motion vector used in the motion compensation process for the sample of the current block (eg, shared MV / shared horizontal or vertical or fractional component / MV ' mentioned above) can be stored in the decoded picture buffer and It may be utilized for motion vector prediction of a subsequent block in another picture.

a. Alternatively, the motion vector used in the motion compensation process for a sample of the current block (eg, shared MV / shared horizontal or vertical or fractional component/MV' as mentioned above) is the subsequent block of the current/other picture. It may not be allowed to be utilized for motion vector prediction of .

i. In one example, the decoded motion vector (eg, MV _b of the item above) may be utilized for motion vector prediction of a subsequent block in the current/different picture.

b. In one example, a motion vector used in a motion compensation process for a sample of a current block may be utilized in a filtering process (eg, deblocking filter/SAO/ALF).

i. Alternatively, the decoded motion vector (eg, the MV _b of the item above) may be used in the filtering process.

c. In one example, such an MV may be derived at the sub-block level and stored for each sub-block.

4. The interpolation filter used in the motion compensation process to derive the predictive block of the current block can be selected depending on whether the resolution of the reference picture is different from the current picture or whether the width and/or height of the reference picture is greater than the resolution of the current picture. suggest that there is

a. In one example, an interpolation filter with fewer taps may be applied when condition A is met, which condition A depends on the dimensions of the current picture and/or reference picture.

i. In one example, condition A is that the resolution of the reference picture is different from the current picture.

ii. In one example, condition A is that the width and/or height of the reference picture is greater than the width of the current picture.

iii. In one example, condition A is W1 > a * W2 and/or H1 > b * H2, where (W1, H1) represents the width and height of the reference picture, and (W2, H2) is the width and height of the current picture Represents the height, where a and b are two factors, for example, a = b = 1.5.

iv. In one example, condition A may also vary depending on whether double prediction is used.

v. In one example, a 1-tap filter is applied. That is, integer pixels without filtering are output as an interpolation result.

vi. In one example, a bi-linear filter is applied when the resolution of the reference picture is different from the current picture.

vii. In one example, when the resolution of the reference picture is different from the current picture, or when the width and/or height of the reference picture is greater than the resolution of the current picture, a 4-tap filter or a 6-tap filter is applied.

One) A 6-tap filter can also be used for affine motion compensation.

2) A four-tap filter can also be used for interpolation of chroma samples.

b. In one example, when the resolution of the reference picture is different from the current picture, or when the width and/or height of the reference picture is greater than the resolution of the current picture, a 4-tap filter or a 6-tap filter is applied.

c. Whether and/or how to apply the method disclosed in item 4 may vary depending on the color component.

i. For example, the method applies only to luma components.

d. Whether and/or how to apply the method disclosed in Item 4 may vary depending on the interpolation filtering direction.

i. For example, the method applies only to horizontal filtering.

ii. For example, the method applies only to vertical filtering.

5. When the resolution of the reference picture is different from the current picture, or when the width and/or height of the reference picture is greater than that of the current picture, it is proposed to apply a two-step process for generating a prediction block.

a. In a first step, a virtual reference block is generated by upsampling or downsampling an area in the reference picture according to the width and/or height of the current picture and the reference picture.

b. In a second step, a prediction sample is generated from the virtual reference block by applying interpolation filtering regardless of the width and/or height of the current picture and the reference picture.

6. It is proposed that the calculation of the upper-left coordinate of the bounding block for reference sample padding (xSbInt _L , ySbInt _L ) as in some embodiments may be derived according to the width and/or height of the current picture and the reference picture.

a. In one example, the luma position of the entire sample unit is modified as follows:

xInt _i = Clip3( xSbInt _L - Dx, xSbInt _L + sbWidth + Ux, xInt _i ),

yInt _i = Clip3( ySbInt _L - Dy, ySbInt _L + sbHeight + Uy, yInt _i ),

Here, Dx and/or Dy and/or Ux and/or Uy may vary depending on the width and/or height of the current picture and the reference picture.

b. In one example, the chroma position of the entire sample unit is modified as follows.

xInti = Clip3( xSbInt _C - Dx, xSbInt _C + sbWidth + Ux, xInti )

yInti = Clip3( ySbInt _C - Dy, ySbInt _C + sbHeight + Uy, yInti )

Here, Dx and/or Dy and/or Ux and/or Uy may vary depending on the width and/or height of the current picture and the reference picture.

7. Instead of storing/using a motion vector for a block based on the same reference picture resolution as the current picture, it is proposed to use an actual motion vector in consideration of the resolution difference.

a. Alternatively, further, when using the motion vector to generate the predictive block, there is no need to further change the motion vector according to the resolution of the current picture and the reference picture (eg, (refx _L , refy _L )).

Interaction between RPR and other coding tools

8. Whether to apply a filtering process (eg, a deblocking filter) may depend on the resolution of the reference picture and/or the resolution of the current picture.

a. In one example, the boundary strength (BS) setting of the deblocking filter may consider the resolution difference in addition to the motion vector difference.

i. In one example, the scaled motion vector difference according to the resolution of the current and reference picture may be used to determine the boundary strength.

b. In one example, when the resolution of the at least one reference picture of block A is different (or less than, greater than, or equal to) the resolution of the at least one reference picture of block B as compared to the case where the same resolution is used for both blocks. case), the strength of the deblocking filter for the boundary between block A and block B may be set differently (eg, increase/decrease).

c. In one example, if the resolution of the at least one reference picture of block A is different from (or less than or greater than) the resolution of the at least one reference picture of block B, the boundary between block A and block B is determined to be filtered. indicated (eg, BS is set to 2).

d. In one example, when the resolution of at least one reference picture of block A and/or block B is different from (or less than, greater than, In the same case), the strength of the deblocking filter on the boundary between the block A and the block B may be set differently (eg, increase/decrease).

e. In one example, if at least one reference picture of at least one of the blocks has a different resolution than the current picture, the boundary between the two blocks is marked as filtered (eg, BS is set to 2) .

9. If a subpicture is present, the conformance bitstream may have to satisfy that the reference picture must have the same resolution as the current picture.

a. Alternatively, when the reference picture has a different resolution than the current picture, there should be no subpictures in the current picture.

b. Alternatively, it is not permitted to use a reference picture of a resolution different from that of the current picture for a subpicture of the current picture.

i. Alternatively, reference picture management may also be called to exclude reference pictures with different resolutions.

10. In one example, subpictures (eg, a method of dividing one picture into multiple subpictures) may be defined separately for pictures with different resolutions.

In one example, the corresponding subpicture of the reference picture may be derived by scaling and/or offsetting the subpicture of the current picture if the reference picture has a different resolution than the current picture.

11. Prediction Refinement with Optical Flow (PROF) may be activated when the reference picture has a different resolution than the current picture.

a. In one example, a set of MVs (denoted as MV _g ) may be generated for a sample group and used for motion compensation as described in item 1. On the other hand, MV (denoted as MV _p ) can be derived for each sample, and the difference between MV _p and MV _g (e.g., corresponding to Δv used in PROF) is the gradient (e.g., motion compensated together with the spatial gradient of the block) can be used to derive prediction refinement.

b. In one example, MV _p may have a different precision than MV _g . For example, MV _p may be 1/N-pel (N > 0) precision, N = 32, 64, or the like.

c. In one example, MV _g may have a different precision than the internal MV precision (eg, 1/16-pel).

d. In one example, prediction refinement is added to the prediction block to produce a refined prediction block.

e. In one example, this method can be applied to each prediction direction.

f. In one example, this method can be applied only in the case of a single prediction.

g. In one example, this method can be applied to single prediction or/and double prediction.

h. In one example, this method can be applied only when the reference picture has a different resolution from the current picture.

12. When the resolution of the reference picture is different from that of the current picture, it is proposed that only one MV can be utilized for a block/subblock to perform a motion compensation process to derive a predictive block of the current block.

a. In one example, a unique MV for a block/subblock may be defined as a function (eg, average) of all MVs associated with each sample within the block/subblock.

b. In one example, the unique MV for a block/subblock may be defined as the selected MV associated with a selected sample (eg, a center sample) within the block/subblock.

c. In one example, only one MV may be utilized in a 4x4 block or subblock (eg, 4x1).

d. In one example, BIO may be further applied to compensate for precision loss due to block-based motion vectors.

13. When the width and/or height of the reference picture is different from the width and/or height of the current picture, a lazy mode that does not signal a block-based motion vector may be applied.

a. In one example, the motion vector may not be signaled and the motion compensation process is to approximate the case of a pure resolution change of a still image.

b. In one example, only motion vectors at the picture/tile/brick/CTU level may be signals and the relevant blocks may use the motion vectors when the resolution is changed.

14. PROF may be applied to coarse motion compensation when the width and/or height of the reference picture is different from the width and/or height of the current picture for a block coded in the affine prediction mode and/or the non-affine prediction mode.

a. In one example, when the width and/or height of the reference picture is different from the width and/or height of the current picture, PROF may be activated.

b. In one example, an affine motion set can be generated by combining the indicated motion and resolution scaling and used by the PROF.

15. Interweaved prediction (eg, proposed in JVET-K0102) may be applied to coarse motion compensation when the width and/or height of the reference picture is different from the width and/or height of the current picture.

a. In one example, the resolution change (zoom) is expressed as an affine motion, and interweave motion prediction may be applied.

16. LMCS and/or chroma residual scaling may be deactivated when the width and/or height of the current picture is different from the width and/or height of the IRAP picture in the same IRAP period.

a. In one example, when LMCS is deactivated, slice level flags such as slice_lmcs_enabled_flag, slice_lmcs_aps_id, and slice_chroma_residual_scale_flag are not signaled and may be inferred to 0.

b. In one example, when chroma residual scaling is deactivated, a slice level flag such as slice_chroma_residual_scale_flag is not signaled and may be inferred to 0.

Restrictions on RPR

17. RPR can be applied to coding blocks with block dimension constraints.

a. In one example, for an MХN coding block, when M is the block width and N is the block height, RPR is used when M*N < T or M*N <= T (eg, T = 256). been done.

b. In one example, when M < K (or M <= K) (eg, K = 16) and/or N < L (or N <= L) (eg, L = 16), RPR may not be used.

18. Bitstream matching may be added to limit the ratio between the width and/or height of the active reference picture (or its compatibility window) and the width and/or height of the current picture (or its compatibility window). Assume that refPicW and refPicH indicate the width and height of the reference picture, and curPicW and curPicH indicate the width and height of the current picture,

a. In one example, when (refPicW χ curPicW) is an integer, the reference picture may be marked as an active reference picture.

i. Alternatively, when (refPicW χ curPicW) is equal to a fraction, the reference picture may be marked as unavailable.

b. In one example, when (refPicW χ curPicW) is equal to (X * n), where X represents a prime number equal to X = 1/2 and n is n = 1, 2, 3, 4 ...., and It represents the same integer, and the reference picture may be indicated as an active reference picture.

i. In one example, if (refPicW χ curPicW) is not equal to (X * n), the reference picture may be marked as unavailable.

19. Whether and/or how to activate a coding tool for an MxN block (e.g., dual prediction/full triangular prediction mode (TPM)/mixing process of TPM) and/or the method depends on the resolution and/or current of the reference picture (or its suitability window). It may depend on the resolution of the picture (or the conformance window).

a. In one example, M*N < T or M*N <= T (eg, T = 64).

b. In one example, M < K (or M <= K) (eg, K = 16) and/or N < L (or N <= L) (eg, L = 16).

c. In one example, the coding tool is not allowed if the width/height of the at least one reference picture is different from the current picture.

i. In one example, the coding tool is not allowed when the width/height of at least one reference picture of the block is greater than the width/height of the current picture.

d. In one example, if the width/height of each reference picture of the block is different from the width/height of the current picture, the coding tool is not allowed.

i. In one example, if the width/height of each reference picture is greater than the width/height of the current picture, the coding tool is not allowed.

e. Alternatively, if the coding tool does not allow, motion compensation may be performed with one MV with a single prediction.

Conformity window related

20. The conformance cropping window offset parameter (eg, conf_win_left_offset) is signaled with N-pel precision instead of 1-pel, where N is a positive integer greater than 1.

a. In one example, the actual offset may be derived as the signaled offset multiplied by N.

b. In one example, M is set to 32 or 16.

21. It is recommended that the conformance cropping window offset parameter not only apply to the output. The specific internal decoding process may depend on the crop picture size (eg, the resolution of the conformance window in the picture).

22. When the width and/or height of the picture indicated by (pic_width_in_luma_samples, pic_height_in_luma_samples) of the first video unit and the second video unit are the same, the conformance cropping window offset of the first video unit (eg, PPS) and the second video unit It is suggested that the parameters may be different.

23. When the width and/or height of a picture represented by (pic_width_in_luma_samples, pic_height_in_luma_samples) in the first video unit and the second video unit are different from each other, the conformance crop window offset of the first video unit (eg, PPS) and the second video unit It is proposed that the parameters should be identical in the conformance bitstream.

a. The conformance crop window offset parameter of the first video unit (eg, PPS) and the second video unit is the same as the width and/or height of the picture indicated by (pic_width_in_luma_samples, pic_height_in_luma_samples) in the first video unit and the second video unit, or It is proposed that they should be identical in the conformance bitstream, irrespective of whether they are identical.

24. It is assumed that the width and height of the conformance window defined in the first video unit (eg, PPS) are denoted by W1 and H1, respectively. The width and height of the conformance window defined in the second video unit (eg, PPS) are denoted by W2 and H2, respectively. The upper left position of the conformance window defined in the first video unit (eg PPS) is denoted by X1 and Y1. The upper left position of the conformance window defined in the second video unit (eg PPS) is denoted by X2 and Y2. The width and height of the encoded/decoded pictures (eg, pic_width_in_luma_samples and pic_height_in_luma_samples) defined in the first video unit (eg, PPS) are denoted by PW1 and PH1, respectively. The width and height of the coded/decoded picture defined in the second video unit (eg, PPS) are indicated by PW2 and PH2.

a. In one example, W1/W2 should be equal to X1/X2 in the conformance bitstream.

i. Alternatively, W1/X1 should be equal to W2/X2 in the conformance bitstream.

ii. Alternatively, W1 * X2 must be equal to W2 * X1 in the conformance bitstream.

b. In one example, H1/H2 should be equal to Y1/Y2 in the conformance bitstream.

i. Alternatively, H1/Y1 should be equal to H2/Y2 in the conformance bitstream.

ii. Alternatively, H1 * Y2 should be equal to H2 * Y1 in the conformance bitstream.

c. In one example, PW1/PW2 should be equal to X1/X2 in the conformance bitstream.

i. Alternatively, PW1/X1 should be the same as PW2/X2 in the conformance bitstream.

ii. Alternatively, PW1 * X2 should be equal to PW2 * X1 in the conformance bitstream.

d. In one example, PH1/PH2 should be equal to Y1/Y2 in the conformance bitstream.

i. Alternatively, PH1/Y1 should be the same as PH2/Y2 in the conformance bitstream.

ii. Alternatively, PH1 * Y2 should be equal to PH2 * Y1 in the conformance bitstream.

e. In one example, PW1/PW2 should be equal to W1/W2 in the conformance bitstream.

i. Alternatively, PW1/W1 should be the same as PW2/W2 in the conformance bitstream.

ii. Alternatively, PW1 * W2 should be equal to PW2 * W1 in the conformance bitstream.

f. In one example, PH1/PH2 should be equal to H1/H2 in the conformance bitstream.

i. Alternatively, PH1/H1 should be the same as PH2/H2 in the conformance bitstream.

ii. Alternatively, PH1 * H2 should be equal to PH2 * H1 in the conformance bitstream.

g. In the conformance bitstream, if PW1 is greater than PW2, then W1 must be greater than W2.

h. In the conformance bitstream, if PW1 is less than PW2, then W1 must be less than W2.

i. In the conformance bitstream, (PW1-PW2) * (W1-W2) MUST not be less than zero.

j. In the conformance bitstream, H1 must be greater than H2 if PH1 is greater than PH2.

k. In the conformance bitstream, H1 must be less than H2 if PH1 is less than PH2.

l. In the conformance bitstream, (PH1-PH2) * (H1-H2) shall not be less than zero.

m. In the conformance bitstream, W1/W2 must not be greater than (must be less than) PW1/PW2 if PW1 >= PW2.

n. In the conformance bitstream, H1/H2 must not be greater than (must be less than) PH1/PH2 if PH1 >= PH2.

25. The width and height of the current picture (the suitability window of) are denoted by W2 and H2, respectively. The width and height of the compatibility window of the reference picture are denoted by W' and H', respectively. Then at least one constraint below must be followed by a conformance bit stream.

a. W * pw >= W'; pw is an integer equal to 2.

b. W * pw > W'; pw is an integer equal to 2.

c. W' * pw' >= W; pw' is an integer equal to 8.

d. W' * pw' > W; pw' is an integer equal to 8.

e. H * ph >= H'; ph is an integer equal to 2.

f. H * ph > H'; ph is an integer equal to 2.

g. H' * ph' >= H; ph' is an integer equal to 8.

h. H' * ph' > H; ph' is an integer equal to 8.

i. In one example, pw is equal to pw'.

j. In one example, ph is equal to ph'.

k. In one example, pw equals ph.

l. In one example, pw' is equal to ph'.

m. In one example, when W and H represent the width and height of the current picture, respectively, the sub-items above may be required to be satisfied by the conformance bitstream. W' and H' represent the width and height of the reference picture.

26. It is proposed that the conformance window parameters are partially signaled.

a. In one example, the top left sample in the relevance window of the picture is the same as the picture's sample.

b. For example, conf_win_left_offset defined in VVC is not signaled and is inferred as 0.

c. For example, conf_win_top_offset defined in VVC is not signaled and is inferred as 0.

27. Position derivation of the reference sample (eg (refx _L , refy _L ) defined in VVC) is the upper left position of the current picture and/or the compatibility window of the reference picture (eg (conf_win_left_offset defined in VVC) , conf_win_top_offset))). 4 shows examples of sample positions derived as in VVC (a) and the proposed method (b). The dashed rectangle represents the fit window.

a. In one example, the dependency exists only when the width and/or height of the current picture and the width and/or height of the reference picture are different.

b. In one example, the derivation of the horizontal position of the reference sample (eg, refx _L defined in VVC) is at the left position of the compatibility window of the current picture and/or reference picture (eg, conf_win_left_offset defined in VVC). may vary depending on

i. In one example, the horizontal position (denoted by xSb') of the current sample relative to the upper left position of the conformance window in the current picture is calculated and used to derive the position of the reference sample.

One) For example, xSb' = xSb - (conf_win_left_offset << Prec) is calculated and used to derive the position of the reference sample, where xSb represents the horizontal position of the current sample in the current picture. conf_win_left_offset indicates the horizontal position of the upper left sample in the matching window of the current picture. Prec represents the precision of xSb and xSb', where (xSb>>Prec) may represent the actual horizontal coordinates of the current sample with respect to the current picture. For example, Prec = 0 or Prec = 4.

ii. In one example, the horizontal position (denoted by Rx') of the reference sample relative to the upper left position of the conformance window in the reference picture is calculated.

One) The calculation of Rx' may depend on xSb' and/or motion vectors, and/or resampling rates.

iii. In one example, the horizontal position (denoted by Rx) of the relative reference sample in the reference picture is calculated according to Rx'.

One) For example, Rx = Rx' + (conf_win_left_offset_ref << Prec) is calculated, where conf_win_left_offset_ref indicates the horizontal position of the upper left sample in the conformance window of the reference picture. Prec represents the precision of Rx and Rx'. For example, Prec = 0 or Prec = 4.

iv. In one example, Rx may be calculated directly according to xSb', and/or a motion vector, and/or a resampling ratio. In other words, the two steps of derivation for Rx' and Rx are combined into one step calculation.

v. Whether and/or how to use the left position (eg, conf_win_left_offset defined in VVC) of the compatibility window of the current picture and/or reference picture may vary according to a color component and/or a color format.

One) For example, conf_win_left_offset may be modified as conf_win_left_offset = conf_win_left_offset * SubWidthC, where SubWidthC defines the horizontal sampling level of the color component. For example, SubWidthC is equal to 1 for the luma component. SubWidthC is equal to 2 for the chroma component when the color format is 4:2:0 or 4:2:2.

2) For example, conf_win_left_offset may be modified as conf_win_left_offset = conf_win_left_offset / SubWidthC, where SubWidthC defines the horizontal sampling step of the color component. For example, SubWidthC is equal to 1 for the luma component. SubWidthC is equal to 2 for the chroma component when the color format is 4:2:0 or 4:2:2.

c. In one example, the derivation of the vertical position of the reference sample (eg, refy _L as defined in VVC) is at the top position of the compatibility window of the current picture and/or reference picture (eg, conf_win_top_offset defined in VVC). can depend on

i. In one example, the vertical position (denoted by ySb′) of the current sample with respect to the upper left position of the conformance window in the current picture is calculated and used to derive the position of the reference sample.

One) For example, ySb'=ySb - (conf_win_top_offset << Prec) is calculated and used to derive the position of the reference sample, where ySb represents the vertical position of the current sample in the current picture. conf_win_top_offset indicates the vertical position of the upper left sample in the suitability window of the current picture. Prec represents the precision of ySb and ySb'. For example, Prec = 0 or Prec = 4.

ii. In one example, the vertical position (denoted by Ry') of the reference sample relative to the upper-left position of the conformance window in the reference picture is calculated.

One) The calculation of Ry' may depend on ySb' and/or a motion vector, and/or a resampling rate.

iii. In one example, the vertical position (denoted by Ry) of the relative reference sample in the reference picture is calculated according to Ry'.

One) For example, Ry = Ry' + (conf_win_top_offset_ref << Prec) is calculated, where conf_win_top_offset_ref indicates the vertical position of the upper left sample in the conformance window of the reference picture. Prec represents the precision of Ry and Ry'. For example, Prec = 0 or Prec = 4.

iv. In one example, Ry may be calculated directly according to ySb' and/or a motion vector, and/or a resampling ratio. That is, the two derivation steps for Ry' and Ry are combined into one step calculation.

v. Whether and/or how to use the top position of the compatibility window of the current picture and/or reference picture (eg, conf_win_top_offset defined in VVC) and/or method may depend on a color component and/or a color format.

One) For example, conf_win_top_offset may be modified as conf_win_top_offset = conf_win_top_offset * SubHeightC, where SubHeightC defines the vertical sampling level of the color component. For example, SubHeightC is equal to 1 for the luma component. SubHeightC is equal to 2 for the chroma component when the color format is 4:2:0.

2) For example, conf_win_top_offset may be modified as conf_win_top_offset = conf_win_top_offset / SubHeightC, where SubHeightC defines the vertical sampling level of the color component. For example, SubHeightC is equal to 1 for the luma component. SubHeightC is equal to 2 for the chroma component when the color format is 4:2:0.

28. It is proposed that the integer part of the horizontal coordinate of the reference sample can be clipped to [minW, maxW]. It is assumed that the width and height of the conformance window of the reference picture are indicated by W1 and H1, respectively. The width and height of the compatibility window of the reference picture are denoted by W' and H'. The upper left position of the conformance window in the reference picture is denoted by (X0, Y0).

a. In one example, minW is equal to zero.

b. In one example, minW is equal to X0.

c. In one example, maxW equals W-1.

d. In one example, maxW equals W'-1.

e. In one example, maxW equals X0+W'-1.

f. In one example, minW and/or maxW may be modified based on color format and/or color component.

i. For example, minW is modified to minW *SubC.

ii. For example, minW is modified to minW /SubC.

iii. For example, maxW is modified to maxW *SubC.

iv. For example, maxW is modified to maxW /SubC.

v. In one example, SubC is equal to 1 for the luma component.

vi. In one example, SubC is equal to 2 for the chroma component when the color format is 4:2:0.

vii. In one example, SubC is equal to 2 for the chroma component when the color format is 4:2:2.

viii. In one example, SubC is equal to 1 for the chroma component when the color format is 4:4:4.

g. In one example, whether and/or how to perform clipping may vary depending on the dimension of the current picture (or the conformance window therein) and the dimension of the reference picture (or the conformance window therein).

i. In one example, clipping is performed only when the dimension of the current picture (or the conformance window therein) is different from the dimension of the reference picture (or the conformance window therein).

29. It is proposed that the integer part of the vertical coordinate of the reference sample can be clipped to [minH, maxH]. It is assumed that the width and height of the conformance window of the reference picture are indicated by W1 and H1, respectively. The width and height of the compatibility window of the reference picture are denoted by W' and H'. The upper left position of the conformance window in the reference picture is denoted by (X0, Y0).

a. In one example, minH is equal to zero.

b. In one example, minH equals Y0.

c. In one example, maxH is equal to H-1.

d. In one example, maxH is equal to H'-1.

e. In one example, maxH is equal to Y0+H'-1.

f. In one example, minH and/or maxH may be modified based on color format and/or color component.

i. For example, minH is modified to minH *SubC.

ii. For example, minH is modified to minH/SubC.

iii. For example, maxH is modified to maxH *SubC.

iv. For example, maxH is modified to maxH /SubC.

v. In one example, SubC is equal to 1 for the luma component.

vi. In one example, SubC is equal to 2 for the chroma component when the color format is 4:2:0.

vii. In one example, SubC is equal to 1 for the chroma component when the color format is 4:2:2.

viii. In one example, SubC is equal to 1 for the chroma component when the color format is 4:4:4.

g. In one example, whether and/or how to perform clipping may vary depending on the dimension of the current picture (or the conformance window therein) and the dimension of the reference picture (or the conformance window therein).

i. In one example, clipping is performed only when the dimension of the current picture (or the conformance window therein) is different from the dimension of the reference picture (or the conformance window therein).

In the following discussion, when two syntax elements have equivalent functions but can be signaled in different video units (eg, VPS/SPS/PPS/slice header/picture header, etc.), the first syntax element is attached to the second syntax element. It is claimed to be "corresponding".

30. A syntax element may be signaled in a first video unit (eg, picture header or PPS) and the corresponding syntax element is at a higher level (eg, SPS) or at a lower level (eg, slice header) It is proposed not to be signaled in the second video unit.

a. Alternatively, the first syntax element may be signaled in a first video unit (eg, a picture header or PPS) and a corresponding second syntax element may be signaled in a second video unit at a lower level (such as a slice header) may be signaled.

i. Alternatively, an indicator may be signaled in the second video unit to indicate whether the second syntax element is signaled later.

ii. In one example, a slice associated with a second video unit (such as a slice header) may follow the indication of the second syntax element instead of the first syntax element when the second syntax element is signaled.

iii. An indicator associated with the first syntax element may be signaled in the first video unit to indicate whether the second syntax element is signaled in any slice (or other video unit) associated with the first video unit.

b. Alternatively, the first syntax element may be signaled in a first video unit of a higher level (eg, VPS/SPS/PPS), and a corresponding second syntax element may be signaled in a second video unit (eg, picture header).

i. Alternatively, the indicator may then be signaled to indicate whether the second syntax element is signaled.

ii. In one example, a picture (which may be split into slices) associated with the second video unit may follow the indication of the second syntax element instead of the first syntax element when the second syntax element is signaled.

c. 픽처 헤더의 제1 신텍스 요소는 섹션 2.6에 지정된 슬라이스 헤더의 제2 신텍스 요소로서 동등한 기능을 가질 수 있으나( slice_temporal_mvp_enabled_flag, cabac_init_flag, six_minus_max_num_merge_cand, five_minus_max_num_subblock_merge_cand, slice_fpel_mmvd_enabled_flag, slice_disable_bdof_dmvr_flag, max_num_merge_cand_minus_max_num_triangle_cand, slice_fpel_mmvd_enabled_flag, slice_six_minus_max_num_ibc_merge_cand, slice_joint_cbcr_sign_flag, slice_qp_delta, . Controls all slices of a picture (such as but not limited to .. ).

d. The first syntax element of the SPS specified in section 2.6 may have the same function as the second syntax element of the picture header (sps_bdof_dmvr_slice_present_flag, Controls only associated pictures (which can be split into slices) such as, but not limited to, sps_mmvd_enabled_flag, sps_isp_enabled_flag, sps_mrl_enabled_flag, sps_mip_enabled_flag, sps_cclm_enabled_flag, sps_mts_enabled_flag...

e. The first syntax element of the PPS specified in section 2.7 may have an equivalent function as the second syntax element of the picture header, but entropy_coding_sync_enabled_flag, Controls only the associated picture (which can be split into slices), such as, but not limited to, entry_point_offsets_present_flag, cabac_init_present_flag, rpl1_idx_present_flag...

31. The syntax element signaled in the picture header is separated from other syntax elements signaled or derived in SPS/VPS/DPS.

32. The DMVR and BDOF activation/deactivation indications may be separately signaled in the picture header instead of being controlled by the same flag (eg, pic_disable_bdof_dmvr_flag).

33. Indication of activation/deactivation of inter prediction via PROF/cross component ALF/geometric partition (GEO) may be signaled in the picture header.

a. Alternatively, the indication of PROF activation/deactivation of the picture header may be signaled conditionally according to the PROF activation flag of the SPS.

b. Alternatively, the CCALF (Cross-Component ALF) activation/deactivation indication of the picture header may be conditionally signaled according to the CCALF activation flag of the SPS.

c. Alternatively, the indication of activating/deactivating GEO in the picture header may be signaled conditionally according to the GEO activation flag of the SPS.

d. Alternatively, also, activation/deactivation indication of PROF/cross component ALF/interface via geometric partition (GEO) in slice header may be conditionally signaled according to a syntax element signaled in picture header instead of SPS.

34. An indication of the prediction type of a slice/brick/tile (or other video unit smaller than a picture) in the same picture may be signaled in the picture header.

a. In one example, an indication of whether all slices/bricks/tiles (or other video units smaller than a picture) are all intra coded (eg, all I slices) can be signaled in the picture header.

i. Alternatively, the slice type may not be signaled in the slice header also if the indication indicates that all slices in the picture are I slices.

b. Alternatively, an indication of whether at least one of a slice/brick/tile (or other video unit smaller than a picture) is not intra-coded (eg, at least one non-I slice) may be signaled in the picture header. .

c. Alternatively, an indication of whether all slices/bricks/tiles (or other video units smaller than a picture) all have the same prediction type (eg, I/P/B slice) can be signaled in the picture header.

i. Alternatively, the slice type may not be signaled in the slice header.

ii. Alternatively, also, the indication of allowed tools for a particular prediction type (eg, DMVR/BDOF/TPM/GEO is only allowed for B slices, and dual tree is allowed only for I slices) depends on the indication of the prediction type. It may be signaled conditionally.

d. Alternatively, furthermore, the signaling of the indication of the activation/deactivation tool may depend on the indication of the prediction type mentioned in the sub-item above.

i. Alternatively, also the indication of the activation/deactivation tool may be derived according to the indication of the prediction type mentioned in the sub-item above.

35. In this specification (items 1 to 29), the term “conformance window” may be replaced with another term such as “scaling window”. The scaling window may be signaled differently than the conformance window, and is used to derive the scaling factor and/or the upper left offset used to derive the reference sample position relative to the RPR.

a. In one example, the scaling window may be constrained by a conformance window. For example, in a conformance bitstream, a scaling window should be included in the conformance window.

36. Whether and/or how to signal the maximum block size allowed for the transform skip coded block may depend on the maximum block size for the transform coded block.

a. Alternatively, the maximum block size for a transform skip coded block cannot be greater than the maximum block size for a transform coded block in the conformance bitstream.

37. Whether to enable an indication to enable Joint Cb-Cr Residue (JCCR) coding (eg sps_joint_cbcr_enabled_flag) and how to signal the color format (eg, 4:0:0, 4 :2:0, etc.)

a. For example, the joint Cb-Cr residual (JCCR) activation indication may not be signaled when the color format is 4:0:0. An example syntax design is as follows:

Downsampling Filter Types for Creating Chroma Blending Masks in TPM/GEO

38. The type of downsampling filter used for blending weights derivation for chroma samples is at the video unit level (eg, SPS/VPS/PPS/Picture header/Subpicture/Slice/Slice header/Tile/Brick/CTU). /VPDU level).

a. In one example, a high level flag may be signaled to switch between different chroma format types of content.

i. In one example, a high level flag may be signaled to switch between chroma format type 0 and chroma format type 2.

ii. In one example, a flag for specifying whether the upper-left downsampled luma weight is collocated with the upper-left luma weight in the TPM/GEO prediction mode (ie, chroma sample location type 0) may be signaled.

iii. In one example, in the TPM/GEO prediction mode, the top left downsampled luma sample coexists horizontally with the top left luma sample, but vertically by 0.5 units of luma samples to the top left luma sample (i.e., chroma sample position type 2). A flag may be signaled to specify whether to shift to .

b. In one example, the type of downsampling filter may be signaled for a 4:2:0 chroma format and/or a 4:2:2 chroma format.

c. In one example, the flag may be signaled to specify the type of chroma downsampling filter used for TPM/GEO prediction.

i. In one example, a flag may be signaled as to whether to use downsampling filter A or downsampling filter B for chroma weight derivation in TPM/GEO prediction mode.

39. The type of downsampling filter used to derive the blending weight for chroma samples is at the video unit level (eg, SPS/VPS/PPS/picture header/subpicture/slice/slice header/tile/brick/CTU/VPDU level) can be derived from

a. In one example, a lookup table may be defined to specify a correspondence between a chroma subsampling filter type and a chroma format type of content.

40. When the chroma sample position type is different, a designated downsampling filter may be used for the TPM/GEO prediction mode.

a. In one example, the chroma weights of the TPM/GEO may be subsampled from the upper left luma weights placed for a particular chroma sample location type (eg, chroma sample location type 0).

b. In one example, for a particular chroma sample location type (eg, chroma sample location type 0 or 2), the specified X-tap filter (where X is a constant equal to X = 6 or 5) is used in the TPM/GEO prediction mode. Can be used for chroma weight subsampling.

41. In a video unit (eg SPS, PPS, picture header, slice header, etc.), the first syntax element (such as a flag) determines whether multiple transform selection (MTS) is disabled for all blocks (slice/picture) may be signaled to indicate

a. A second syntax element indicating how to apply an MTS (eg, MTS activation/deactivation MTS/implicit MTS/explicit MTS) to an intra coding block (slice/picture) is conditionally signaled with respect to the first syntax element . For example, the second syntax element is signaled only when the first syntax element indicates that MTS is not disabled for all blocks (slice/picture).

b. A third syntax element indicating how to apply an MTS (eg, MTS activation/deactivation MTS/implicit MTS/explicit MTS) to an inter-coding block (slice/picture) is conditionally signaled with respect to the first syntax element . For example, the third syntax element is signaled only when the first syntax element indicates that MTS is not disabled for all blocks (slice/picture).

c. An exemplary syntax design is as follows.

d. The third syntax element may be conditionally signaled according to whether sub-block transform (SBT) is applied. An exemplary syntax design is as follows.

e. An exemplary syntax design is as follows.

Deciding to use Coding Tool X

42. The decision of whether to activate the coding tool X and/or how to activate it may depend on the width and/or height of one or multiple reference pictures and/or pictures of consideration of the current picture.

a. The width and/or height of one or multiple reference pictures and/or pictures of the current picture may be modified to make a decision.

b. A picture to be considered may be defined by a conformance window or a scaling window.

i. A picture under consideration may be an entire picture.

c. In one example, whether and/or how to activate the coding tool X may depend on the width of the picture minus one or multiple offsets horizontally and/or the height of the picture minus the offset in the vertical direction.

i. In one example, the horizontal offset may be defined as scaling_win_left_offset.

ii. In one example, the vertical offset may be defined as scaling_win_top_offset.

iii. In one example, the horizontal offset may be defined as (scaling_win_right_offset + scaling_win_left_offset).

iv. In one example, the vertical offset may be defined as (scaling_win_bottom_offset + scaling_win_top_offset).

v. In one example, the horizontal offset may be defined as SubWidthC * ( scaling_win_right_offset + scaling_win_left_offset ).

vi. In one example, the vertical offset may be defined as SubHeightC * ( scaling_win_bottom_offset + scaling_win_top_offset ).

d. In one example, if at least one of the two considering the reference picture has a different resolution (width or height) than the current picture, the coding tool X is deactivated.

i. Alternatively, if at least one of the two output reference pictures has a larger dimension (width or height) than the current picture, the coding tool X is deactivated.

e. In one example, if the person considering the reference picture for the reference picture list L has a different resolution than the current picture, the coding tool X is deactivated for the reference picture list L.

i. Alternatively, if considering the reference picture for the reference picture list L has a larger dimension (width or height) than the current picture, the coding tool X is deactivated for the reference picture list L.

f. In one example, if two considered reference pictures of two reference picture lists have different resolutions, the coding tool may be deactivated.

i. Alternatively, the indication of the coding tool may be signaled conditionally according to the resolution.

ii. Alternatively, the signaling of the indication of the coding tool may be skipped.

g. In one example, in two cases to consider the reference pictures of two merging candidates used to derive the first pairwise merging candidate for at least one reference picture list, the coding tool may be deactivated, for example, The first pairwise merge candidate is marked as unavailable.

i. Alternatively, when considering the reference pictures of two merging candidates utilized to derive the first pairwise merging candidates for both reference picture lists, the coding tool may be deactivated, for example, by the first pairwise Merge candidates are marked as unavailable.

h. In one example, the decoding process of the coding tool may be modified to account for picture dimensions.

i. In one example, the derivation of the MVD relative to another reference picture list (eg, List 1) of the SMVD may be based on a resolution difference (eg, a scaling factor) of at least one of two target SMVD reference pictures. .

ii. In one example, the derivation of the pairwise merging candidate may be based on a resolution difference (eg, a scaling factor) of at least one of the two reference pictures associated with the two reference pictures, eg, a linear weighting instead of the same weight. An average may be applied.

i. In one example, X may be

i. DMVR/BDOF/PROF/SMVD/MMVD/other coding tools to refine motion/prediction on decoder side

ii. TMVP/other coding tools rely on temporal motion information

iii. MTS or other transform coding tool

iv. CC-ALF

v. TPM

vi. GEO

vii. Switchable interpolation filters (e.g. alternative interpolation filters for half-pixel motion compensation)

viii. A mixed process of TPM/GEO/other coding tools that splits one block into multiple partitions.

ix. Coding tool that responds to information stored in a picture different from the current picture

x. Pairwise merge candidates (pairwise merge candidates are not created unless certain conditions related to resolution are met)

xi. Double prediction using CU level weighting (BCW).

xii. weighted prediction.

xiii. affine prediction

xiv. Adaptive Motion Vector Resolution (AMVR)

43. Whether to signal and/or how to signal the use of a coding tool may vary depending on the width and/or height of one or multiple reference pictures and/or pictures under consideration of the current picture.

a. The width and/or height of one or multiple reference pictures and/or pictures of the current picture may be modified to make a decision.

b. A picture to be considered may be defined by a conformance window or a scaling window as defined in JVET-P0590.

xv. A picture under consideration may be an entire picture.

c. In one example, X may be adaptive motion vector resolution (AMVR).

d. In one example, X may be a merge with MV difference (MMVD) method.

xvi. In one example, the configuration of the symmetric motion vector difference reference index may depend on the picture resolution/indication of RPR cases for different reference pictures.

e. In one example, X may be a Symmetric MVD (SMVD) method.

f. In one example, X may be a QT/BT/TT or other partition type.

g. In one example, X may be bi-directional prediction using CU-level weighting (BCW).

h. In one example, X may be a weighted prediction.

i. In one example, X may be an affine prediction.

j. In one example, whether to signal the indication of use of half-pixel motion vector precision/switchable interpolation filter may depend on whether resolution information/RPR is activated for the current block.

k. In one example, signaling of amvr_precision_idx may vary depending on whether resolution information/RPR is activated for the current block.

l. In one example, signaling of sym_mvd_flag/mmvd_merge_flag may vary depending on whether resolution information/RPR is activated for the current block.

m. A conformance bitstream is a 1/2-pixel MV and/or MVD precision (e.g. alternative interpolation filter/switchable interpolation filter) not allowed.

44. It is proposed that AMVR with 1/2 pixel MV and/or MVD precision (or alternative interpolation filter/switchable interpolation filter) can still be activated for a block of RPR.

a. Alternatively, other interpolation filters may also be applied for blocks with 1/2-pels or other precision.

45. In the above item, checking the condition of the same/different resolution can be replaced by adding a flag for the reference picture and checking the flag related to the reference picture.

a. In one example, a process of setting a flag to true or false (eg, to indicate whether a reference picture is an RPR case or a non-RPR case) may be called during the reference picture list construction process.

xvii. For example, the following may apply:

fRefWidth is the value of the reference picture RefPicList[i][j] in luma samples. It is set equal to PicOutputWidthL, where PicOutputWidthL indicates the width of a picture to be considered of a reference picture.

fRefWidth is the value of the reference picture RefPicList[i][j] in luma samples. It is set equal to PicOutputHeightL, where PicOutputHeightL indicates the height of the picture to be considered of the reference picture.

RefPicScale[ i ][ j ][ 0 ] = ( ( fRefWidth << 14 ) + ( PicOutputWidthL >> 1 ) ) / PicOutputWidthL, where PicOutputWidthL represents the width of the picture to be considered of the current picture.

RefPicScale[ i ][ j ][ 1 ] = ( ( fRefHeight << 14 ) + ( PicOutputHeightL >> 1 ) ) / PicOutputHeightL, where PicOutputWidthL indicates the height of the picture under consideration of the current picture.

RefPicIsScaled[ i ][ j ] = ( RefPicScale[　i　][　j　][　0　] != ( 1 << 14 ) ) | |

( RefPicScale[　i　][　j　][　1　] != ( 1 << 14 ) )

Here, RefPicList[ i ][ j ] indicates the j-th reference picture in the reference picture list i.

b. In one example, when RefPicIsScaled[ 0 ][ refIdxL0 ] is not equal to zero or RefPicIsScaled[ 1 ][ refIdxL1 ] is not equal to zero, coding tool X (eg, DMVR/BDOF/SMVD/MMVD/thoseD/PROF mentioned above) may be disabled.

c. In one example, if both RefPicIsScaled[ 0 ][ refIdxL0 ] and RefPicIsScaled[ 1 ][ refIdxL1 ] are not equal to 0, then coding tool X (eg, DMVR/BDOF/SMVD/MMVD/SMVD/PROF/above items mentioned in the item) ) can be deactivated.

d. In one example, when RefPicIsScaled[ 0 ][ refIdxL0 ] is not equal to 0, coding tool X (eg, PROF or those mentioned in the item above) may be deactivated for reference picture list 0.

e. In one example, when RefPicIsScaled[ 1 ][ refIdxL1 ] is not equal to 0, coding tool X (eg, PROF or those mentioned in the bullet above) may be disabled for reference picture list 1 .

46. The SAD and/or threshold used by the BDOF/DMVR may vary depending on the bit depth.

f. In one example, the calculated SAD value may first be shifted by a function of bit depth before being utilized to be compared to a threshold.

g. In one example, the calculated SAD value may be directly compared to a modified threshold, which may depend on a function of bit depth.

5. Additional Examples

In the following text changes are indicated in bold, underlined italics.

5.1. Implementation of constraints on the conformance window

conf_win_left_offset, conf_win_right_offset, conf_win_top_offset and conf_win_bottom_offset specify picture samples of CVS output in the decoding process in terms of the rectangular area specified in picture coordinates for output. When conformance_window_flag is equal to 0, the values of conf_win_left_offset, conf_win_right_offset, conf_win_top_offset, and conf_win_bottom_offset are inferred to be equal to 0.

적합성 크로핑 윈도우는 SubWidthC　*　conf_win_left_offset to pic_width_in_luma_samples　-　(　SubWidthC　*　conf_win_right_offset　+　1　의 수평 픽처 좌표 및 SubHeightC　*　conf_win_top_offset to pic_height_in_luma_samples　-　(　SubHeightC　*　conf_win_bottom_offset　+　1　)의 수직 픽처 좌표가 포함되는 좌표를 갖는 루마 샘플을 포함한다 .

The value of SubWidthC * ( conf_win_left_offset + conf_win_right_offset ) must be less than pic_width_in_luma_samples, and the value of SubHeightC * ( conf_win_top_offset + conf_win_bottom_offset ) must be less than pic_height_in_luma_samples.

The PicOutputWidthL and PicOutputHeightL variables are derived as follows:

PicOutputWidthL = pic_width_in_luma_samples - (7-43)

SubWidthC * ( conf_win_right_offset + conf_win_left_offset )

PicOutputHeightL = pic_height_in_pic_size_units - (7-44) SubHeightC * ( conf_win_bottom_offset + conf_win_top_offset )

When ChromaArrayType is non-zero, the corresponding specified samples of both chroma arrays are samples with picture coordinates ( x / SubWidthC, y / SubHeightC ), where ( x, y ) is the picture coordinate of the specified luma sample.

Let refPicOutputWidthL and refPicOutputHeightL be PicOutputWidthL and PicOutputHeightL of the reference picture of the current picture referring to this PPS, respectively. A bitstream conformance requirement where all of the following conditions are met:

- PicOutputWidthL * 2 must be greater than or equal to refPicOutputWidthL.

- PicOutputHeightL * 2 must be greater than or equal to refPicOutputHeightL.

- PicOutputWidthL must be less than or equal to refPicOutputWidthL * 8.

- PicOutputHeightL must be less than or equal to refPicOutputHeightL * 8.

5.2. Example 1 of Reference Sample Position Derivation

8.5.6.3.1 General

...

The variable fRefWidth is set equal to PicOutputWidthL of the reference picture in luma samples.

The variable fRefHeight is set equal to PicOutputHeightL of the reference picture in the luma sample.

The variable fRefLeftOff is set equal to conf_win_left_offset of the reference picture in the luma sample.

The variable fRefTopOff is set equal to conf_win_top_offset of the reference picture in the luma sample.

It is set equal to the motion vector mvLX (refMvLX - mvOffset).

- If cIdx is 0, the following applies.

- Scaling factors and fixed-point representations are defined as follows.

hori_scale_fp =((fRefWidth << 14) +(PicOutputWidthL >> 1))/PicOutputWidthL (8-753)

vert_scale_fp =((fRefHeight << 14) +(PicOutputHeightL >> 1))/PicOutputHeightL (8-754)

- (xIntL, yIntL) is the luma position given in whole sample units and (xFracL, yFracL) is the offset given in 1/16 sample units. These variables are used only in this section to specify the fractional sample location inside the reference sample array refPicLX.

- The upper left coordinate of the boundary block for reference sample padding (xSbIntL, ySbIntL) is set equal to (xSb +(mvLX [0] >> 4), ySb +(mvLX [1] >> 4)).

- for each luma sample position (x _L = 0..sbWidth - 1 + brdExtSize, y _L = 0..sbHeight - 1 + brdExtSize) in the predicted luma sample array predSamplesLX, the corresponding predicted luma sample value predSamplesLX [x _L ] [y _L ] is derived as:

- (refxSb _L , refySb _L ) and (refx _L , refy _L ) are the luma positions pointed to by motion vectors (refMvLX [0], refMvLX [1]) specified in 1/16-sample units. The variables refxSb _L , refx _L , refySb _L and refy _L are derived as follows:

refxSb _L = (( ( xSb - conf_win_left_offset) << 4 ) + refMvLX[ 0 ] ) * hori_scale_fp (8-755)

refx _L =((Sign(refxSb) *((Abs(refxSb) + 128) >> 8)

+ x _L *((hori_scale_fp + 8) >> 4)) + 32) >> 6 (8-756)

refySb _L = ( ( (ySb - conf_win_top_offset) << 4 ) + refMvLX[ 1 ] ) * vert_scale_fp (8-757)

refyL =((Sign(refySb) *((Abs(refySb) + 128) >> 8) + yL *

( ( vert_scale_fp + 8 ) >> 4 ) ) + 32 ) >> 6 (8-758)

- refx _L = refx _L +( fRefLeftOff<<4).

- refy _L = refy _L +( fRefTopOff<<4).

- xInt _L , yInt _L , xFrac _L and yFrac _L variables are derived as follows:

xInt _L = refx _L >> 4 (8-759)

yInt _L = refy _L >> 4 (8-760)

xFrac _L = refx _L & 15 (8-761)

yFrac _L = refy _L & 15 (8-762)

- If bdofFlag is equal to TRUE ( sps_affine_prof_enabled_flag is TRUE and inter_affine_flag[ xSb ][ ySb ] is equal to TRUE, and one or more of the following conditions are true, the predicted luma sample value predSamplesLX[ x _L ][ y _L ] ( xIntL + ( xFrac _L >> 3 ) - 1), yInt _L + ( yFrac _L >> 3 ) - 1 ) and refPicLX as inputs, the luma integer sample specified in section 8.5.6.3.3 Derived by invoking the import process.

- x _L is equal to zero.

- x _L is equal to sbWidth + 1.

- y _L is equal to 0.

- y _L is equal to sbHeight + 1.

- Otherwise, the predicted luma sample values predSamplesLX[xL][yL] are (xIntL-(brdExtSize > 0? 1: 0), yIntL-(brdExtSize > 0? 1: 0)), (xFracL, yFracL), (xSbIntL, ySbIntL), refPicLX, hpelIfIdx, sbWidth, sbHeight, and (xSb, ySb) are derived by invoking the luma sample 8-tap interpolation filtering process specified in section 8.5.6.3.2 as input.

- Otherwise (cIdx is not 0), the following applies:

Let (xIntC, yIntC) be the chroma position given in whole sample units and (xFracC, yFracC) be the offset given in 1/32 sample units. These variables are used only in this section to specify common fractional sample locations within the reference sample array refPicLX.

- The upper-left coordinates of the bounding block for the reference sample padding (xSbIntC, ySbIntC) are ((xSb/SubWidthC) +(mvLX [0] >> 5), (ySb/SubHeightC) +(mvLX [1 ] >> 5)) is set the same as

- For each chroma sample position (xC = 0..sbWidth - 1, yC = 0 .. sbHeight - 1) in the predicted chroma sample array predSamplesLX, the corresponding predicted chroma sample value predSamplesLX [xC] [yC] is derived as do:

- Let (refxSb _C , refySb _C ) and (refx _C , refy _C ) be the chroma positions pointed to by the motion vectors (mvLX [0], mvLX [1]) given in 1/32 sample units. The variables refxSb _C , refySb _C , refx _C and refy _C are derived as follows:

refxSbC = ((( xSb - conf_win_left_offset) / SubWidthC << 5 ) + mvLX[ 0 ] ) * hori_scale_fp (8-763)

refx _C =((Sign(refxSb _C ) *((Abs(refxSb _C ) + 256) >> 9)

+ xC * ( ( hori_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-764)

refySbC = ( ((ySb - conf_win_top_offset) / SubHeightC << 5 ) + mvLX[ 1 ] ) * vert_scale_fp (8-765)

refy _C =((Sign(refySb _C ) *((Abs(refySb _C ) + 256) >> 9)

+ yC* ( ( vert_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-766)

- refx _C = refx _C +( fRefLeftOff/ SubWidthC <<5).

- refy _C = refy _C +( fRefTopOff/ SubHeightC <<5).

- xInt _C , yInt _C , xFrac _C and yFrac _C variables are derived as follows:

xInt _C = refx _C >> 5 (8-767)

yInt _C = refy _C >> 5 (8-768)

xFrac _C = refy _C & 31 (8-769)

yFrac _C = refy _C & 31 (8-770)

5.3. Example 2 of Reference Sample Position Derivation

8.5.6.3.1 General

...

The variable fRefWidth is set equal to PicOutputWidthL of the reference picture in luma samples.

The variable fRefHeight is set equal to PicOutputHeightL of the reference picture in the luma sample.

The variable fRefLeftOff is set equal to conf_win_left_offset of the reference picture in the luma sample.

The variable fRefTopOff is set equal to conf_win_top_offset of the reference picture in the luma sample.

It is set equal to the motion vector mvLX (refMvLX - mvOffset).

- If cIdx is 0, the following applies.

- Scaling factors and fixed-point representations are defined as follows.

hori_scale_fp =((fRefWidth << 14) +(PicOutputWidthL >> 1))/PicOutputWidthL (8-753)

vert_scale_fp =((fRefHeight << 14) +(PicOutputHeightL >> 1))/PicOutputHeightL (8-754)

- (xIntL, yIntL) is the luma position given in whole sample units and (xFracL, yFracL) is the offset given in 1/16 sample units. These variables are used only in this section to specify the fractional sample location inside the reference sample array refPicLX.

- The upper left coordinate of the boundary block for reference sample padding (xSbIntL, ySbIntL) is set equal to (xSb +(mvLX [0] >> 4), ySb +(mvLX [1] >> 4)).

- for each luma sample position (x _L = 0..sbWidth - 1 + brdExtSize, y _L = 0..sbHeight - 1 + brdExtSize) in the predicted luma sample array predSamplesLX, the corresponding predicted luma sample value predSamplesLX [x _L ] [y _L ] is derived as:

- (refxSb _L , refySb _L ) and (refx _L , refy _L ) are the luma positions pointed to by motion vectors (refMvLX [0], refMvLX [1]) specified in 1/16-sample units. The variables refxSb _L , refx _L , refySb _L and refy _L are derived as follows:

refxSb _L = (( ( xSb - conf_win_left_offset) << 4 ) + refMvLX[ 0 ] ) * hori_scale_fp (8-755)

refx _L =((Sign(refxSb) *((Abs(refxSb) + 128) >> 8)

+ x _L * ( ( hori_scale_fp + 8 ) >> 4 ) ) +( fRefLeftOff<<10) + 32 ) >> 6 (8-756)

refySb _L = ( ( (ySb - conf_win_top_offset) << 4 ) + refMvLX[ 1 ] ) * vert_scale_fp (8-757)

refyL =((Sign(refySb) *((Abs(refySb) + 128) >> 8) + yL *

( ( vert_scale_fp + 8 ) >> 4 ) ) +( fRefTopOff<<10) + 32 ) >> 6 (8-758)

- xInt _L , yInt _L , xFrac _L and yFrac _L variables are derived as follows:

xInt _L = refx _L >> 4 (8-759)

yInt _L = refy _L >> 4 (8-760)

xFrac _L = refx _L & 15 (8-761)

yFrac _L = refy _L & 15 (8-762)

- If bdofFlag is equal to TRUE ( sps_affine_prof_enabled_flag is TRUE and inter_affine_flag[ xSb ][ ySb ] is equal to TRUE, and one or more of the following conditions are true, the predicted luma sample value predSamplesLX[ x _L ][ y _L ] ( xIntL + ( xFrac _L >> 3 ) - 1), yInt _L + ( yFrac _L >> 3 ) - 1 ) and refPicLX as inputs, the luma integer sample specified in section 8.5.6.3.3 Derived by invoking the import process.

- x _L is equal to zero.

- x _L is equal to sbWidth + 1.

- y _L is equal to 0.

- y _L is equal to sbHeight + 1.

- Otherwise, the predicted luma sample values predSamplesLX[xL][yL] are (xIntL-(brdExtSize > 0? 1: 0), yIntL-(brdExtSize > 0? 1: 0)), (xFracL, yFracL), (xSbIntL, ySbIntL), refPicLX, hpelIfIdx, sbWidth, sbHeight, and (xSb, ySb) are derived by invoking the luma sample 8-tap interpolation filtering process specified in section 8.5.6.3.2 as input.

- Otherwise (cIdx is not 0), the following applies:

Let (xIntC, yIntC) be the chroma position given in whole sample units and (xFracC, yFracC) be the offset given in 1/32 sample units. These variables are used only in this section to specify common fractional sample locations within the reference sample array refPicLX.

- The upper-left coordinates of the bounding block for reference sample padding (xSbIntC, ySbIntC) are ((xSb/SubWidthC) +(mvLX [0] >> 5), (ySb/SubHeightC) +(mvLX [1 ] >> 5) ) is set the same as

- For each chroma sample position (xC = 0..sbWidth - 1, yC = 0 .. sbHeight - 1) in the predicted chroma sample array predSamplesLX, the corresponding predicted chroma sample value predSamplesLX [xC] [yC] is derived as do:

- Let (refxSb _C , refySb _C ) and (refx _C , refy _C ) be the chroma positions pointed to by the motion vectors (mvLX [0], mvLX [1]) given in 1/32 sample units. The variables refxSb _C , refySb _C , refx _C and refy _C are derived as follows:

refxSbC = ((( xSb - conf_win_left_offset) / SubWidthC << 5 ) + mvLX[ 0 ] ) * hori_scale_fp (8-763)

refx _C =((Sign(refxSb _C ) *((Abs(refxSb _C ) + 256) >> 9)

+ xC * ( ( hori_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-764)

refySbC = ( ((ySb - conf_win_top_offset) / SubHeightC << 5 ) + mvLX[ 1 ] ) * vert_scale_fp (8-765)

refy _C =((Sign(refySb _C ) *((Abs(refySb _C ) + 256) >> 9)

+ yC* ( ( vert_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-766)

- refx _C = refx _C +( fRefLeftOff/ SubWidthC <<5).

- refy _C = refy _C +( fRefTopOff/ SubHeightC <<5).

The xInt _C , yInt _C , xFrac _C and yFrac _C variables are derived as follows:

xInt _C = refx _C >> 5 (8-767)

yInt _C = refy _C >> 5 (8-768)

xFrac _C = refy _C & 31 (8-769)

yFrac _C = refy _C & 31 (8-770)

5.4. Example 3 of Reference Sample Position Derivation

8.5.6.3.1 General

...

The variable fRefWidth is set equal to PicOutputWidthL of the reference picture in luma samples.

The variable fRefHeight is set equal to PicOutputHeightL of the reference picture in the luma sample.

The variable fRefLeftOff is set equal to conf_win_left_offset of the reference picture in the luma sample.

The variable fRefTopOff is set equal to conf_win_top_offset of the reference picture in the luma sample.

It is set equal to the motion vector mvLX (refMvLX - mvOffset).

- If cIdx is 0, the following applies.

- Scaling factors and fixed-point representations are defined as follows.

hori_scale_fp =((fRefWidth << 14) +(PicOutputWidthL >> 1))/PicOutputWidthL (8-753)

vert_scale_fp =((fRefHeight << 14) +(PicOutputHeightL >> 1))/PicOutputHeightL (8-754)

- (xIntL, yIntL) is the luma position given in whole sample units and (xFracL, yFracL) is the offset given in 1/16 sample units. These variables are used only in this section to specify the fractional sample location inside the reference sample array refPicLX.

- The upper left coordinate of the boundary block for reference sample padding (xSbIntL, ySbIntL) is set equal to (xSb +(mvLX [0] >> 4), ySb +(mvLX [1] >> 4)).

- for each luma sample position (x _L = 0..sbWidth - 1 + brdExtSize, y _L = 0..sbHeight - 1 + brdExtSize) in the predicted luma sample array predSamplesLX, the corresponding predicted luma sample value predSamplesLX [x _L ] [y _L ] is derived as:

- (refxSb _L , refySb _L ) and (refx _L , refy _L ) are the luma positions pointed to by motion vectors (refMvLX [0], refMvLX [1]) specified in 1/16-sample units. The variables refxSb _L , refx _L , refySb _L and refy _L are derived as follows:

refxSb _L = (( ( xSb - conf_win_left_offset) << 4 ) + refMvLX[ 0 ] ) * hori_scale_fp (8-755)

refx _L =((Sign(refxSb) *((Abs(refxSb) + 128) >> 8)

+ x _L * ( ( hori_scale_fp + 8 ) >> 4 ) ) +( fRefLeftOff<<10) + 32 ) >> 6 (8-756)

refySb _L = ( ( (ySb - conf_win_top_offset) << 4 ) + refMvLX[ 1 ] ) * vert_scale_fp (8-757)

refyL =((Sign(refySb) *((Abs(refySb) + 128) >> 8) + yL *

( ( vert_scale_fp + 8 ) >> 4 ) ) +( fRefTopOff<<10) + 32 ) >> 6 (8-758)

- xInt _L , yInt _L , xFrac _L and yFrac _L variables are derived as follows:

xInt _L = refx _L >> 4 (8-759)

yInt _L = refy _L >> 4 (8-760)

xFrac _L = refx _L & 15 (8-761)

yFrac _L = refy _L & 15 (8-762)

- If bdofFlag is equal to TRUE ( sps_affine_prof_enabled_flag is TRUE and inter_affine_flag[ xSb ][ ySb ] is equal to TRUE, and one or more of the following conditions are true, the predicted luma sample value predSamplesLX[ x _L ][ y _L ] ( xIntL + ( xFrac _L >> 3) - 1), yInt _L + ( yFrac _L >> 3 ) - 1 ) and refPicLX as inputs, the luma integer sample specified in section 8.5.6.3.3 Derived by invoking the import process.

- x _L is equal to zero.

- x _L is equal to sbWidth + 1.

- y _L is equal to 0.

- y _L is equal to sbHeight + 1.

- The predicted luma sample values predSamplesLX[ xL ][ yL ] invoke the luma sample 8-tap interpolation filtering process specified in section 8.5.7.3.2 using ( xIntL, yIntL ), ( xFracL, yFracL ), refPicLX and padVal as inputs. is induced by Use 1　:　0　),　yIntL　-　(　brdExtSize　>　0　?　1　:　0 ) ), ( xFracL, yFracL ), and (xSbIntL, sb.SbWidth), (xSbIntL, ySbIntL), enter (xSbIntL, ySbIntsb) as

- Otherwise (cIdx is not 0), the following applies:

Let (xIntC, yIntC) be the chroma position given in whole sample units and (xFracC, yFracC) be the offset given in 1/32 sample units. These variables are used only in this section to specify common fractional sample locations within the reference sample array refPicLX.

- The upper-left coordinates of the bounding block for reference sample padding (xSbIntC, ySbIntC) are ((xSb/SubWidthC) +(mvLX [0] >> 5), (ySb/SubHeightC) +(mvLX [1 ] >> 5) ) is set the same as

- for each chroma sample position (xC = 0..sbWidth - 1, yC = 0 .. sbHeight - 1) in the predicted chroma sample array predSamplesLX, the corresponding predicted chroma sample value predSamplesLX [xC] [yC] is is derived:

- Let (refxSb _C , refySb _C ) and (refx _C , refy _C ) be the chroma positions pointed to by the motion vectors (mvLX [0], mvLX [1]) given in 1/32 sample units. The variables refxSb _C , refySb _C , refx _C and refy _C are derived as follows:

refxSbC = ((( xSb - conf_win_left_offset) / SubWidthC << 5 ) + mvLX[ 0 ] ) * hori_scale_fp (8-763)

refx _C =((Sign(refxSb _C ) *((Abs(refxSb _C ) + 256) >> 9)

+ xC * ( ( hori_scale_fp + 8 ) >> 4 ) ) + ( fRefLeftOff/ SubWidthC <<10) + 16 ) >> 5 (8-764)

refySbC = ( ((ySb - conf_win_top_offset) / SubHeightC << 5 ) + mvLX[ 1 ] ) * vert_scale_fp (8-765)

refy _C =((Sign(refySb _C ) *((Abs(refySb _C ) + 256) >> 9)

+ yC* ( ( vert_scale_fp + 8 ) >> 4 ) ) + ( fRefTopOff/ SubHeightC <<10) + 16 ) >> 5 (8-766)

- xInt _C , yInt _C , xFrac _C and yFrac _C variables are derived as follows:

xInt _C = refx _C >> 5 (8-767)

yInt _C = refy _C >> 5 (8-768)

xFrac _C = refy _C & 31 (8-769)

yFrac _C = refy _C & 31 (8-770)

5.5. Example 1 of Reference Sample Position Clipping

8.5.6.3.1 General

Inputs to this process are:

- Luma position (xSb, ySb) designating the upper left sample of the current coding subblock based on the upper left luma sample of the current picture,

- Variable sbWidth to designate the width of the current coding subblock,

- Variable sbHeight to designate the height of the current coding subblock,

- motion vector offset mvOffset,

- stylish motion vector refMvLX,

- selected reference picture sample array refPicLX,

- half-sample interpolation filter index hpelIfIdx,

- bidirectional optical flow flag bdofFlag,

- Variable cIdx designating the color component index of the current block.

The output of this process is:

- (sbWidth　+　brdExtSize)x(sbHeight　+　brdExtSize) array predSamplesLX of prediction

- The prediction block boundary extension size brdExtSize is derived as follows:

brdExtSize = (　bdofFlag |　| (　inter_affine_flag[　xSb　][　ySb　] && sps_affine_prof_enabled_flag　)　) ? 2: 0 (8-752)

The variable fRefWidth is set equal to PicOutputWidthL of the reference picture in luma samples.

The variable fRefHeight is set equal to PicOutputHeightL of the reference picture in the luma sample.

It is set equal to the motion vector mvLX (refMvLX - mvOffset).

- If cIdx is 0, the following applies.

- Scaling factors and fixed-point representations are defined as follows.

hori_scale_fp =((fRefWidth << 14) +(PicOutputWidthL >> 1))/PicOutputWidthL (8-753)

vert_scale_fp =((fRefHeight << 14) +(PicOutputHeightL >> 1))/PicOutputHeightL (8-754)

- (xIntL, yIntL) is the luma position given in whole sample units and (xFracL, yFracL) is the offset given in 1/16 sample units. These variables are used only in this section to specify the fractional sample location inside the reference sample array refPicLX.

- The upper left coordinate of the boundary block for reference sample padding (xSbIntL, ySbIntL) is set equal to (xSb +(mvLX [0] >> 4), ySb +(mvLX [1] >> 4)).

- for each luma sample position in the predicted luma sample array predSamplesLX (x _L = 0..sbWidth - 1 + brdExtSize, y _L = 0..sbHeight - 1 + brdExtSize), the corresponding predicted luma sample value predSamplesLX [x _L ] [y _L ] is derived as:

- (refxSb _L , refySb _L ) and (refx _L , refy _L ) are the luma positions pointed to by motion vectors (refMvLX [0], refMvLX [1]) specified in 1/16-sample units. The variables refxSb _L , refx _L , refySb _L and refy _L are derived as follows:

refxSb _L = ( ( xSb << 4 ) + refMvLX[ 0 ] ) * hori_scale_fp (8-755)

refx _L =((Sign(refxSb) *((Abs(refxSb) + 128) >> 8)

+ x _L *((hori_scale_fp + 8) >> 4)) + 32) >> 6 (8-756)

refySb _L = ( ( ySb << 4 ) + refMvLX[ 1 ] ) * vert_scale_fp (8-757)

refyL =((Sign(refySb) *((Abs(refySb) + 128) >> 8) + yL *

( ( vert_scale_fp + 8 ) >> 4 ) ) + 32 ) >> 6 (8-758)

- xInt _L , yInt _L , xFrac _L and yFrac _L variables are derived as follows:

xInt _L = Clip3( 0, fRefWidth -1, refxL >> 4) (8-759)

yInt _L = Clip3( 0, fRefHeight -1, refyL >> 4) (8-760)

xFrac _L = refx _L & 15 (8-761)

yFrac _L = refy _L & 15 (8-762)

- If bdofFlag is equal to TRUE ( sps_affine_prof_enabled_flag is TRUE and inter_affine_flag[ xSb ][ ySb ] is equal to TRUE, and one or more of the following conditions are true, the predicted luma sample value predSamplesLX[ x _L ][ y _L ] ( xIntL + ( xFrac _L >> 3) - 1), yInt _L + ( yFrac _L >> 3 ) - 1 ) and refPicLX as inputs, the luma integer sample specified in section 8.5.6.3.3 Derived by invoking the import process.

- x _L is equal to zero.

- x _L is equal to sbWidth + 1.

- y _L is equal to 0.

- y _L is equal to sbHeight + 1.

- Otherwise, the predicted luma sample values predSamplesLX[xL][yL] are (xIntL-(brdExtSize > 0? 1: 0), yIntL-(brdExtSize > 0? 1: 0)), (xFracL, yFracL), (xSbIntL) , ySbIntL), refPicLX, hpelIfIdx, sbWidth, sbHeight, and (xSb, ySb) are derived by invoking the luma sample 8-tap interpolation filtering process specified in section 8.5.6.3.2 as input.

- Otherwise (cIdx is not 0), the following applies:

Let (xIntC, yIntC) be the chroma position given in whole sample units and (xFracC, yFracC) be the offset given in 1/32 sample units. These variables are used only in this section to specify common fractional sample locations within the reference sample array refPicLX.

- The upper-left coordinates of the bounding block for reference sample padding (xSbIntC, ySbIntC) are ((xSb/SubWidthC) +(mvLX [0] >> 5), (ySb/SubHeightC) +(mvLX [1 ] >> 5) ) is set the same as

- for each chroma sample position (xC = 0..sbWidth - 1, yC = 0 .. sbHeight - 1) in the predicted chroma sample array predSamplesLX, the corresponding predicted chroma sample value predSamplesLX [xC] [yC] is is derived:

- Let (refxSb _C , refySb _C ) and (refx _C , refy _C ) be the chroma positions pointed to by the motion vectors (mvLX [0], mvLX [1]) given in 1/32 sample units. The variables refxSb _C , refySb _C , refx _C and refy _C are derived as follows:

refxSb _C = ( ( xSb / SubWidthC << 5 ) + mvLX[ 0 ] ) * hori_scale_fp (8-763)

refx _C =((Sign(refxSb _C ) *((Abs(refxSb _C ) + 256) >> 9)

+ xC * ( ( hori_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-764)

refySb _C = ( ( ySb / SubHeightC << 5 ) + mvLX[ 1 ] ) * vert_scale_fp (8-765)

refy _C =((Sign(refySb _C ) *((Abs(refySb _C ) + 256) >> 9)

+ yC* ( ( vert_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-766)

- xInt _C , yInt _C , xFrac _C and yFrac _C variables are derived as follows:

xInt _C = Clip3( 0, fRefWidth/ SubWidthC -1, refxC >> 5) (8-767)

yInt _C = Clip3( 0, fRefHeight/ SubHeightC -1, refyC >> 5) (8-768)

xFrac _C = refy _C & 31 (8-769)

yFrac _C = refy _C & 31 (8-770)

- The predicted sample values predSamplesLX[xC][yC] are obtained by calling the process specified in 8.5.6.3.4 with (xIntC, yIntC), (xFracC, yFracC), (xSbIntC, ySbIntC), sbWidth, sbHeight and refPicLX as inputs. is derived:

5.6. Example 2 of Reference Sample Position Clipping

8.5.6.3.1 General

Inputs to this process are:

- Luma position (xSb, ySb) designating the upper left sample of the current coding subblock based on the upper left luma sample of the current picture,

- Variable sbWidth to designate the width of the current coding subblock,

- Variable sbHeight to designate the height of the current coding subblock,

- motion vector offset mvOffset,

- stylish motion vector refMvLX,

- selected reference picture sample array refPicLX,

- half-sample interpolation filter index hpelIfIdx,

- bidirectional optical flow flag bdofFlag,

- Variable cIdx designating the color component index of the current block.

The output of this process is:

- (sbWidth　+　brdExtSize)x(sbHeight　+　brdExtSize) array predSamplesLX of prediction

The prediction block boundary extension size brdExtSize is derived as follows:

brdExtSize = (　bdofFlag |　| (　inter_affine_flag[　xSb　][　ySb　] && sps_affine_prof_enabled_flag　)　) ? 2: 0 (8-752)

The variable fRefWidth is set equal to PicOutputWidthL of the reference picture in luma samples.

The variable fRefHeight is set equal to PicOutputHeightL of the reference picture in the luma sample.

The variable fRefLeftOff is set equal to conf_win_left_offset of the reference picture in the luma sample.

The variable fRefTopOff is set equal to conf_win_top_offset of the reference picture in the luma sample.

It is set equal to the motion vector mvLX (refMvLX - mvOffset).

- If cIdx is 0, the following applies.

- Scaling factors and fixed-point representations are defined as follows.

hori_scale_fp =((fRefWidth << 14) +(PicOutputWidthL >> 1))/PicOutputWidthL (8-753)

vert_scale_fp =((fRefHeight << 14) +(PicOutputHeightL >> 1))/PicOutputHeightL (8-754)

- (xIntL, yIntL) is the luma position given in whole sample units and (xFracL, yFracL) is the offset given in 1/16 sample units. These variables are used only in this section to specify the fractional sample location inside the reference sample array refPicLX.

- The upper left coordinate of the boundary block for reference sample padding (xSbIntL, ySbIntL) is set equal to (xSb +(mvLX [0] >> 4), ySb +(mvLX [1] >> 4)).

- for each luma sample position in the predicted luma sample array predSamplesLX (x _L = 0..sbWidth - 1 + brdExtSize, y _L = 0..sbHeight - 1 + brdExtSize), the corresponding predicted luma sample value predSamplesLX [x _L ] [y _L ] is derived as:

- (refxSb _L , refySb _L ) and (refx _L , refy _L ) are the luma positions pointed to by motion vectors (refMvLX [0], refMvLX [1]) specified in 1/16-sample units. The variables refxSb _L , refx _L , refySb _L and refy _L are derived as follows:

refxSb _L = ( ( xSb << 4 ) + refMvLX[ 0 ] ) * hori_scale_fp (8-755)

refx _L =((Sign(refxSb) *((Abs(refxSb) + 128) >> 8)

+ x _L *((hori_scale_fp + 8) >> 4)) + 32) >> 6 (8-756)

refySb _L = ( ( ySb << 4 ) + refMvLX[ 1 ] ) * vert_scale_fp (8-757)

refyL =((Sign(refySb) *((Abs(refySb) + 128) >> 8) + yL *

( ( vert_scale_fp + 8 ) >> 4 ) ) + 32 ) >> 6 (8-758)

- xInt _L , yInt _L , xFrac _L and yFrac _L variables are derived as follows:

xInt _L = Clip3( fRefLeftOff, fRefLeftOff +fRefWidth -1, refxL >> 4) (8-759)

yInt _L = Clip3( fRefTopOff, fRefTopOff +fRefHeight -1, refyL >> 4) (8-760)

xFrac _L = refx _L & 15 (8-761)

yFrac _L = refy _L & 15 (8-762)

- If bdofFlag is equal to TRUE ( sps_affine_prof_enabled_flag is TRUE and inter_affine_flag[ xSb ][ ySb ] is equal to TRUE, and one or more of the following conditions are true, the predicted luma sample value predSamplesLX[ x _L ][ y _L ] ( xIntL + ( xFrac _L >> 3) - 1), yInt _L + ( yFrac _L >> 3 ) - 1 ) and refPicLX as inputs, the luma integer sample specified in section 8.5.6.3.3 Derived by invoking the import process.

- x _L is equal to zero.

- x _L is equal to sbWidth + 1.

- y _L is equal to 0.

- y _L is equal to sbHeight + 1.

- Otherwise, the predicted luma sample values predSamplesLX[xL][yL] are (xIntL-(brdExtSize > 0? 1: 0), yIntL-(brdExtSize > 0? 1: 0)), (xFracL, yFracL), (xSbIntL) , ySbIntL), refPicLX, hpelIfIdx, sbWidth, sbHeight, and (xSb, ySb) are derived by invoking the luma sample 8-tap interpolation filtering process specified in section 8.5.6.3.2 as input.

- Otherwise (cIdx is not 0), the following applies:

Let (xIntC, yIntC) be the chroma position given in whole sample units and (xFracC, yFracC) be the offset given in 1/32 sample units. These variables are used only in this section to specify common fractional sample locations within the reference sample array refPicLX.

- The upper-left coordinates of the bounding block for reference sample padding (xSbIntC, ySbIntC) are ((xSb/SubWidthC) +(mvLX [0] >> 5), (ySb/SubHeightC) +(mvLX [1 ] >> 5) ) is set the same as

- for each chroma sample position (xC = 0..sbWidth - 1, yC = 0 .. sbHeight - 1) in the predicted chroma sample array predSamplesLX, the corresponding predicted chroma sample value predSamplesLX [xC] [yC] is is derived:

- Let (refxSb _C , refySb _C ) and (refx _C , refy _C ) be the chroma positions pointed to by the motion vectors (mvLX [0], mvLX [1]) given in 1/32 sample units. The variables refxSb _C , refySb _C , refx _C and refy _C are derived as follows:

refxSb _C = ( ( xSb / SubWidthC << 5 ) + mvLX[ 0 ] ) * hori_scale_fp (8-763)

refx _C =((Sign(refxSb _C ) *((Abs(refxSb _C ) + 256) >> 9)

+ xC * ( ( hori_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-764)

refySb _C = ( ( ySb / SubHeightC << 5 ) + mvLX[ 1 ] ) * vert_scale_fp (8-765)

refy _C =((Sign(refySb _C ) *((Abs(refySb _C ) + 256) >> 9)

+ yC* ( ( vert_scale_fp + 8 ) >> 4 ) ) + 16 ) >> 5 (8-766)

- xInt _C , yInt _C , xFrac _C and yFrac _C variables are derived as follows:

xInt _C = Clip3( fRefLeftOff / SubWidthC, (fRefWidth + fRefLeftOff )/ SubWidthC -1, refxC >> 5) (8-767)

yInt _C = Clip3( fRefTopOff / SubHeightC, (fRefHeight + fRefTopOff )/ SubHeightC -1, refyC >> 5) (8-768)

xFrac _C = refy _C & 31 (8-769)

yFrac _C = refy _C & 31 (8-770)

- The predicted sample values predSamplesLX[xC][yC] are obtained by calling the process specified in 8.5.6.3.4 with (xIntC, yIntC), (xFracC, yFracC), (xSbIntC, ySbIntC), sbWidth, sbHeight and refPicLX as inputs. is derived:

5.7. Embodiment of usage of coding tools

5.7.1 BDOF on/off control

- The variable currPic designates the current picture and the variable bdofFlag is derived as follows.

- If all of the following conditions are true, bdofFlag is set equal to true.

- sps_bdof_enabled_flag is 1 and slice_disable_bdof_dmvr_flag is 0.

- predFlagL0[xSbIdx][ySbIdx] and predFlagL1[xSbIdx][ySbIdx] are both 1.

- DiffPicOrderCnt( currPic, RefPicList[ 0 ][ refIdxL0 ] ) is the same as DiffPicOrderCnt( RefPicList[ 1 ][ refIdxL1 ], currPic).

- RefPicList[ 0 ][ refIdxL0 ] is a short-term reference picture and RefPicList[ 1 ][ refIdxL1 ] is a short-term reference picture.

- MotionModelIdc[ xCb ][ yCb ] is equal to 0.

- merge_subblock_flag[ xCb ][ yCb ] is equal to 0.

- sym_mvd_flag[ xCb ][ yCb ] is equal to 0.

- ciip_flag[ xCb ][ yCb ] is equal to 0.

- BcwIdx[ xCb ][ yCb ] is equal to 0.

- luma_weight_l0_flag[ refIdxL0 ] and luma_weight_l1_flag[ refIdxL1 ] are both equal to 0.

- cbWidth is greater than or equal to 8.

- cbHeight is greater than or equal to 8.

- cbHeight * cbWidth is greater than or equal to 128.

- RefPicIsScaled[ 0 ][ refIdxL0 ] is equal to 0 and RefPicIsScaled[ 1 ][ refIdxL1 ] is equal to 0.

- cIdx is equal to 0.

- Otherwise, bdofFlag is set equal to FALSE.

5.7.2 DMVR on/off control

- dmvrFlag is set equal to 1 if all of the following conditions are true:

- sps_dmvr_enabled_flag is equal to 1 and slice_disable_bdof_dmvr_flag is equal to 0.

- general_merge_flag[ xCb ][ yCb ] is equal to 1.

- both predFlagL0[ 0 ][ 0 ] and predFlagL1[ 0 ][ 0 ] are equal to 1.

- mmvd_merge_flag[ xCb ][ yCb ] is equal to 0.

- ciip_flag[ xCb ][ yCb ] is equal to 0.

- DiffPicOrderCnt( currPic, RefPicList[ 0 ][ refIdxL0 ]) is the same as DiffPicOrderCnt( RefPicList[ 1 ][ refIdxL1 ], currPic ).

- RefPicList[ 0 ][ refIdxL0 ] is a short-term reference picture and RefPicList[ 1 ][ refIdxL1 ] is a short-term reference picture.

- BcwIdx[ xCb ][ yCb ] is equal to 0.

- both luma_weight_l0_flag[ refIdxL0 ] and luma_weight_l1_flag[ refIdxL1 ] are equal to 0.

- cbWidth is greater than or equal to 8.

- cbHeight is greater than or equal to 8.

- cbHeight*cbWidth is greater than or equal to 128.

- RefPicIsScaled[ 0 ][ refIdxL0 ] is equal to 0 and RefPicIsScaled[ 1 ][ refIdxL1 ] is equal to 0.

5.7.3 PROF on/off control for reference picture list X

The variable cbProfFlagLX is derived as follows:

- If one or more of the following conditions are true, cbProfFlagLX is set equal to FALSE.

- sps_affine_prof_enabled_flag is equal to 0.

- fallbackModeTriggered is equal to 1.

- numCpMv is 2, cpMvLX[ 1 ][ 0 ] is cpMvLX[ 0 ][ 0 ], and cpMvLX[ 1 ][ 1 ] is the same as cpMvLX[ 0 ][ 1 ].

- numCpMv is 3, cpMvLX[ 1 ][ 0 ] equals cpMvLX[ 0 ][ 0 ], cpMvLX[ 1 ][ 1 ] equals cpMvLX[ 0 ][ 1 ], cpMvLX[ 2 ][ 0 ] equals cpMvLX It is the same as [　0　][　0　], and cpMvLX[　2　][　1　] is the same as cpMvLX[　0　][　1　].

- RefPicIsScaled[ X ][ refIdxLX ] is equal to 0.

- [[The pic_width_in_luma_samples of the reference picture refPicLX associated with [refIdxLX] are not the same as the pic_width_in_luma_samples of the current picture, respectively.

- The pic_height_in_luma_samples of the reference picture refPicLX associated with the refIdxLX are not the same as the pic_height_in_luma_samples of the current picture, respectively.]]

- Otherwise, cbProfFlagLX is set equal to TRUE.

5.7.4 PROF on/off control for reference picture list X (second embodiment)

The variable cbProfFlagLX is derived as follows:

- If one or more of the following conditions are true, cbProfFlagLX is set equal to FALSE.

- sps_affine_prof_enabled_flag is equal to 0.

- fallbackModeTriggered is equal to 1.

- numCpMv is 2, cpMvLX[ 1 ][ 0 ] is cpMvLX[ 0 ][ 0 ], and cpMvLX[ 1 ][ 1 ] is the same as cpMvLX[ 0 ][ 1 ].

- numCpMv is 3, cpMvLX[ 1 ][ 0 ] equals cpMvLX[ 0 ][ 0 ], cpMvLX[ 1 ][ 1 ] equals cpMvLX[ 0 ][ 1 ], cpMvLX[ 2 ][ 0 ] equals cpMvLX It is the same as [　0　][　0　], and cpMvLX[　2　][　1　] is the same as cpMvLX[　0　][　1　].

- RefPicIsScaled[ 0 ][ refIdxL0 ] and RefPicIsScaled[ 1 ][ refIdxL1 ] are equal to 0.

- [[The pic_width_in_luma_samples of the reference picture refPicLX associated with [refIdxLX] are not the same as the pic_width_in_luma_samples of the current picture, respectively.

- The pic_height_in_luma_samples of the reference picture refPicLX associated with the refIdxLX are not the same as the pic_height_in_luma_samples of the current picture, respectively.]]

- Otherwise, cbProfFlagLX is set equal to TRUE.

6. Examples of implementations of the disclosed technology

5 is a block diagram of a video processing apparatus 500 . Apparatus 500 may be used to implement one or more of the methods described herein. The device 500 may be implemented as a smartphone, tablet, computer, Internet of Things (IoT) receiver, or the like. The apparatus 500 may include one or more processors 502 , one or more memories 504 , and video processing hardware 506 . The processor(s) 502 may be configured to implement one or more methods described herein. Memory 504 may be used to store data and code used to implement the methods and techniques described herein. The video processing hardware 506 may be used to implement some of the techniques described herein in hardware circuitry, and may be part or all of the processor 502 (eg, a graphics processor core GPU or other signal processing circuitry). ).

In this document, the term “video processing” may refer to video encoding, video decoding, video compression, or video decompression. For example, a video compression algorithm may be applied during transformation from a pixel representation of a video to a corresponding bitstream representation or vice versa. The bitstream representation of the current video block may, for example, correspond to bits that are spread or co-located at different locations within the bitstream as defined by the syntax. For example, a macroblock may be encoded in terms of transformed and coded error residual values and also using bits in the header and other fields in the bitstream.

It will be appreciated that the disclosed methods and techniques will benefit video encoder and/or decoder embodiments integrated within video processing devices, such as smartphones, laptops, desktops, and similar devices, by allowing use of the techniques disclosed herein. .

6 is a flowchart of an exemplary method 600 of video processing. The method 600 includes, at 610 , performing a transform between a current video block and a coded representation of the current video block, wherein the resolution and/or size of the reference picture during the transform is determined by the resolution and/or size of the current video block. If different from size, the same interpolation filter is applied to adjacent or non-adjacent sample groups predicted using the current video block.

Various techniques and embodiments may be described using the following clause-based format.

One. A video processing method comprising:

performing a transform between the current video block and a coded representation of the current video block, wherein if the resolution and/or size of the reference picture is different from the resolution and/or size of the current video block during transformation, converting the current video block The same interpolation filter is applied to groups of adjacent or non-adjacent samples predicted using

2. In the method of Section 1, the same interpolation filter is a vertical interpolation filter.

3. In the method of Section 1, the same interpolation filter is a horizontal interpolation filter.

4. In the method of clause 1, the group of adjacent or non-adjacent samples includes all samples located in the region of the current video block.

5. In the method of Section 4, the current video block is divided into a number of rectangles each of size MXN.

6. In the method of clause 5, M and/or N are predetermined.

7. In the method of clause 5, M and/or N are derived from the dimension of the current video block.

8. In the method of clause 5, M and/or N are signaled in the coded representation of the current video block.

9. In the method of clause 1, a group of samples share the same motion vector.

10. In the method of clause 9, groups of samples share the same horizontal component and/or the same fractional portion of the horizontal component.

11. In the method of clause 9, the groups of samples share the same vertical component and/or the same fractional portion of the vertical component.

12. 12. The method of one or more of claims 9 to 11, wherein the same motion vector or component thereof is selected based on at least one of: a resolution of a reference picture, a size of a reference picture, a current video block, a size of the current video block, or a precision value. meet the above rules.

13. The method of one or more of clauses 9 to 11, wherein the same motion vector or component thereof corresponds to motion information of a sample located in the current video block.

14. In the method of one or more of clauses 9 to 11, the same motion vector or a component thereof is set as motion information of a virtual sample located inside or outside the group.

15. A video processing method comprising:

performing a transform between a current video block and a coded representation of the current video block, wherein, during transform, a resolution and/or size of a reference picture is different from a resolution and/or size of the current video block, wherein the current video A block predicted using a block is allowed to use only integer-valued motion information associated with the current block.

16. In the method of clause 15, integer-valued motion information is derived by rounding up the original motion information of the current video block.

17. In the method of clause 15, the original motion information of the current video block is in the horizontal direction and/or the vertical direction.

18. A video processing method comprising:

performing a transform between a current video block and a coded representation of the current video block, wherein, during transform, if a resolution and/or size of a reference picture is different from a resolution and/or size of the current video block, the current video block An interpolation filter is applied to derive a predicted block using

19. In the method of clause 18, whether the rule relates to the size and/or resolution of the reference picture relative to the resolution and/or size of the current video block.

20. In the method of clause 18, the interpolation filter is a vertical interpolation filter.

21. In the method of clause 18, the interpolation filter is a horizontal interpolation filter.

22. In the method of clause 18, the interpolation filter is one of a 1-tap filter, a bilinear filter, a 4-tap filter, or a 6-tap filter.

23. In the method of section 22, an interpolation filter is used as part of the other steps of the transform.

24. The method of clause 18, wherein the interpolation filter comprises the use of padding samples.

25. In the method of clause 18, the use of the interpolation filter depends on the color component of a sample of the current video block.

26. A video processing method comprising:

performing transformation between the current video block and the coded representation of the current video block, wherein during transformation, if the resolution and/or size of the reference picture is different from the resolution and/or size of the current video block, The blocking filter is applied, and the strength of the deblocking filter is set according to a rule related to the size and/or resolution of the reference picture relative to the resolution and/or size of the current video block.

27. In the method of clause 27, the strength of the deblocking filter varies from video block to video block.

28. A video processing method comprising:

performing a transform between a current video block and a coded representation of the current video block, wherein, during the transform, if a subpicture of the current video block exists, the conformance bitstream is a reference to the resolution and/or size of the current video block It satisfies the rules related to the resolution and/or size of the picture.

29. In the method of section 28,

partitioning the current video block into one or more subpictures, wherein the partitioning depends at least on a resolution of the current video block.

30. A video processing method comprising:

performing a transform between the current video block and a coded representation of the current video block, wherein during the transform, a reference picture of the current video block is resampled according to a rule based on a dimension of the current video block. .

31. A video processing method comprising:

performing a transform between the current video block and a coded representation of the current video block, wherein during the transform, use of a coding tool for the current video block is a reference of the current video block to a resolution/size of the current video block. It is selectively activated or deactivated according to the resolution/size of the picture.

32. In the method of any one or more of the preceding clauses, the group of samples is placed in a fit window.

33. The method of clause 32, wherein the conformance window is rectangular in shape.

34. The method of any one or more of the preceding clauses, wherein the resolution relates to a resolution of a coded/decoded video block or a resolution of a conformance window of a coded/decoded video block.

35. In the method of any one or more of the preceding clauses, the size pertains to the size of the coded/decoded video block or the size of the conformance window in the coded/decoded video block.

36. The method of any one or more of the preceding clauses, wherein dimension dms relates to a dimension of a coded/decoded video block or a dimension of a conformance window of a coded/decoded video block.

37. In the method of clause 32, the conformance window is defined by a set of conformance cropping window parameters.

38. The method of clause 37, wherein at least a portion of the set of conformance cropping window parameters is signaled implicitly or explicitly in the coded representation.

39. In the method of any one or more of the preceding clauses, the set of conformance cropping window parameters is not allowed to be signaled in the coded representation.

40. In the method of any one or more of the preceding clauses, the position of the reference sample is derived with respect to the top left sample of the current video block in the conformance window.

41. A video processing method comprising:

performing a transform between the multiple video blocks and the coded representation of the multiple video blocks, wherein during transform, a first conformance window for a first video block and a second for a second video block A second conformance window is defined, and the ratio of the width and/or height of the first conformance window to the second conformance window obeys at least a rule based on the conformance bitstream.

42. A video decoding apparatus comprising a processor configured to implement the method recited in one or more of clauses 1-41.

43. A video encoding apparatus comprising a processor configured to implement the method recited in one or more of clauses 1-41.

44. A computer program having computer code stored therein, wherein the code, when executed by a processor, causes the processor to implement the method recited in any one of clauses 1-41.

45. Methods, devices and systems described herein.

9 is a block diagram illustrating an example video processing system 900 in which the various techniques disclosed herein may be implemented. Various implementations may include some or all of the components of system 900 . System 900 can include an input 902 for receiving video content. The video content may be received in raw or uncompressed format, eg, 8 or 10-bit multi-component pixel values, or may be in a compressed or encoded format. Input 902 may represent a network interface, a peripheral bus interface, or a storage interface. Examples of network interfaces include wired interfaces such as Ethernet, Passive Optical Network (PON), and the like, and wireless interfaces such as Wi-Fi or cellular interfaces.

System 900 can include a coding component 904 that can implement the various coding or encoding methods described herein. Coding component 904 can reduce an average bitrate of the video from an input 702 to an output of the coding component 904 to produce a coded representation of the video. Therefore, the coding technique is also called video compression or video transcoding technique. The output of the coding component 904 may be stored or transmitted over coupled communications, as represented by the component 906 . The stored or communicated bitstream (or coded) representation of video received at input 902 may be used by component 908 to generate displayable video or pixel values that are sent to display interface 910 . The process of creating user-viewable video from a bitstream representation is also known as video decompression. Also, although certain video processing operations are referred to as “coding” operations or tools, the coding tools or operations are used at the encoder and the corresponding decoding tools or operations that return the coding results are performed by the decoder. will understand

Examples of the peripheral bus interface or the display interface may include a universal serial bus (USB) or a high-definition multimedia interface (HDMI), a display port, or the like. Examples of storage interfaces include Serial Advanced Technology Attachment (SATA), PCI, and IDE interfaces. The techniques described herein may be implemented in a variety of electronic devices, such as cell phones, notebook computers, smart phones, or other devices capable of digital data processing and/or video display.

10 is a block diagram illustrating an example video coding system 100 that may utilize techniques of this disclosure.

As shown in FIG. 10 , the video coding system 100 may include a source device 110 and a destination device 120 . The source device 110 generates encoded video data, which may be referred to as a video encoding device. The destination device 120 may decode the encoded video data generated by the source device 110 , which may be referred to as a video decoding device.

The source device 110 may include a video source 112 , a video encoder 114 , and an input/output (I/O) interface 116 .

The video source 112 may include a video capture device, an interface to receive video data from a video content provider, a computer graphics system for generating the video data, or a combination of these sources. The video data may include one or more pictures. The video encoder 114 encodes the video data of the video source 112 to generate a bitstream. A bitstream may contain a sequence of bits that form a coded representation of video data. The bitstream may include coded pictures and related data. A coded picture is a coded representation of the picture. Related data may include sequence parameter sets, picture parameter sets, and other syntax structures. The I/O interface 116 may include a modulator/demodulator (modem) and/or a transmitter. The encoded video data may be transmitted directly to the destination device 120 via the I/O interface 116 over the network 130a. The encoded video data may be stored in the storage medium/server 130b for access by the destination device 120 .

The destination device 120 may include an I/O interface 126 , a video decoder 124 , and a display device 122 .

I/O interface 126 may include a receiver and/or a modem. I/O interface 126 may obtain encoded video data from source device 110 or storage medium/server 130b. The video decoder 124 may decode the encoded video data. The display device 122 may display the decoded video data to the user. The display device 122 may be integrated with the target device 120 or may be located outside the target device 120 configured to interface with an external display device.

Video encoder 114 and video decoder 124 may operate according to video compression standards, such as high efficiency video coding (HEVC) standards, general purpose video coding (VVC) standards, and other current and/or additional standards.

11 is a block diagram illustrating an example of a video encoder 200 , which may be the video encoder 114 of the system 100 illustrated in FIG. 10 . 10.

The video encoder 200 may be configured to perform any or all of the techniques of this disclosure. In the example of FIG. 9 , video encoder 200 includes a plurality of functional components. The techniques described in this disclosure may be shared among various components of the video encoder 200 . In some examples, a processor may be configured to perform any or all described in this disclosure.

The functional components of the video encoder 200 include a partition unit 201 , a mode select unit 203 , a motion estimation unit 204 , and motion compensation. A prediction unit 202 , which may include a motion compensation unit 205 and an intra prediction unit 206 , and a residual generation unit 207 , a trans A transform unit 208 , a quantization unit 209 , an inverse quantization unit 210 , an inverse transform unit 211 , a reconstruction unit ) 212 , a buffer 213 , and an entropy encoding unit 214 .

In other examples, video encoder 200 may include more, fewer, or other functional components. In one example, the prediction unit 202 may include an intra block copy (IBC) unit. The IBC unit may perform prediction when at least one reference picture is a picture having a current video block in the IBC mode.

Moreover, some components, such as the motion estimation unit 204 and the motion compensation unit 205 , may be highly integrated, but are represented in the example of FIG. 5 as separate for illustrative purposes.

The partition unit 201 may partition a picture into one or more video blocks. The video encoder 200 and the video decoder 300 may support various video block sizes.

The mode selection unit 203 selects a coding mode, for example, intra or inter, etc. based on the error result, and provides the result intra or inter coded block to the residual generating unit 207 to provide residual block data generated and provided to the reconstruction unit 212 to reconstruct an encoded block for use as a reference picture. In some examples, the mode selection unit 203 may select a combination of intra and inter prediction (CIIP) modes, in which the prediction is based on the inter prediction signal and the intra prediction signal. The mode selection unit 203 may also select the resolution (eg, sub-pixel or integer pixel precision) of the motion vector for the block in case of inter prediction.

To perform inter prediction on the current video block, the motion estimation unit 204 may compare one or more reference frames to the current video block in the buffer 213 to generate motion information for the current video block. The motion compensation unit 205 may determine the predictive video block for the current video block based on the decoded picture samples and motion information from the buffer 213 other than the picture associated with the current video block.

The motion estimation unit 204 and the motion compensation unit 205 may perform different operations on the current video block depending on whether the current video block is in an I slice, a P slice, or a B slice.

In some examples, motion estimation unit 204 may perform uni-directional prediction for a current video block, and motion estimation unit 204 may list a reference video block for the current video block. You can search for a reference picture of 0 or List 1. Then, the motion estimation unit 204 generates a reference index indicating the reference picture in list 0 or list 1 including the motion vector and the reference video block indicating the spatial displacement between the current video block and the reference video block. can do. The motion estimation unit 204 may output the reference index, the prediction direction indicator, and the motion vector as motion information of the current video block. The motion compensation unit 205 may generate the predicted video block of the current block based on the reference video block indicated by the motion information of the current video block.

In another example, the motion estimation unit 204 may perform bi-directional prediction on the current video block, and the motion estimation unit 204 lists a reference video block for the current video block. You can search for a reference picture in 0, and also search for a reference picture in list 1 for another reference video block for the current video block. Then, the motion estimation unit 204 may generate a reference index indicating the reference picture in list 0 and list 1 including the motion vector and the reference video block indicating the spatial displacement between the reference video block and the current video block. The motion estimation unit 204 may output a reference index and a motion vector of the current video block as motion information of the current video block. The motion compensation unit 205 may generate the predictive video block of the current video block based on the reference video block indicated by the motion information of the current video block.

In some examples, the motion estimation unit 204 may output the entire set of motion information for decoding processing of the decoder.

In some examples, motion estimation unit 204 may not output the entire set of motion information for the current video. Rather, the motion estimation unit 204 may signal the motion information of the current video block with reference to the motion information of another video block. For example, the motion estimation unit 204 may determine that motion information of a current video block is sufficiently similar to motion information of a neighboring video block.

In one example, the motion estimation unit 204 may indicate a value indicating to the video decoder 300 that the current video block has the same motion information as other video blocks in a syntax structure associated with the current video block.

In another example, motion estimation unit 204 can identify, in a syntax structure associated with the current video block, another video block and a motion vector difference (MVD). The motion vector difference represents the difference between the motion vector of the current video block and the motion vector of the displayed video block. The video decoder 300 may use the motion vector and motion vector difference of the indicated video block to determine the motion vector of the current video block.

As described above, video encoder 200 can predictively signal motion vectors. Two examples of prediction signaling techniques that may be implemented by video encoder 200 include advanced motion vector prediction (AMVP) and merge mode signaling.

The intra prediction unit 206 may perform intra prediction on the current video block. When the intra prediction unit 206 performs intra prediction on the current video block, the intra prediction unit 206 may generate prediction data for the current video block based on decoded samples of other video blocks in the same picture. have. The prediction data for the current video block may include the predicted video block and various syntax elements.

The residual generating unit 207 may generate residual data for the current video block by subtracting a predictive video block (eg, indicated by a minus sign) of the predicted video block from the current video block. The residual data of the current video block may include residual video blocks corresponding to different sample components of a sample in the current video block.

In another example, there may be no residual data for the current video block for the current video block, eg, in a skip mode, the residual generating unit 207 may not perform a subtraction operation.

The transform processing unit 208 may apply one or more transforms to the residual video block associated with the current video block to generate one or more transform coefficient video blocks for the current video block.

After the transform processing unit 208 generates a transform coefficient video block associated with the current video block, the quantization unit 209 is configured to generate a transform coefficient video block associated with the current video block based on one or more quantization parameter (QP) values associated with the current video block. A transform coefficient video block can be quantized.

The inverse quantization unit 210 and the inverse transform unit unit 211 may apply an inverse quantization unit and an inverse transform unit to the transform coefficient video block, respectively, to reconstruct the residual video block from the transform coefficient video block. The reconstruction unit 212 adds the reconstructed residual video block to a corresponding sample from the one or more predicted video blocks generated by the prediction unit 202 and stores the reconstructed video block associated with the current block in the buffer 213 . can create

After the reconstruction unit 212 reconstructs the video block, a loop filtering operation is performed to reduce video blocking artifacts in the video block.

Entropy encoding unit 214 may receive data from another functional component of video encoder 200 . When entropy encoding unit 214 receives the data, entropy encoding unit 214 may perform one or more entropy encoding operations to generate entropy encoded data and output a bitstream including the entropy encoded data. .

12 is a block diagram illustrating an example of a video decoder 300 , which may be a video decoder 114 in the system 100 shown in FIG. 10 .

The video decoder 300 may be configured to perform any or all of the techniques of this disclosure. In the example of FIG. 10 , video decoder 300 includes a plurality of functional components. The techniques described in this disclosure may be shared among various components of the video decoder 300 . In some examples, a processor may be configured to perform any or all described in this disclosure.

In the example of FIG. 10 , a video decoder 300 includes an entropy decoding unit 301 , a motion compensation unit 302 , and an intra prediction unit 303 . ), an inverse quantization unit 304 , an inverse transformation uni 305 , and a reconstruction unit 305 , and a reconstruction unit 306 and a buffer 307 . include Video decoder 300 may, in some examples, perform decoding passes generally reciprocal to the encoding pass described for video encoder 200 (eg, FIG. 9 ).

The entropy decoding unit 301 may retrieve the encoded bitstream. The encoded bitstream may include entropy coded video data (eg, an encoded block of video data). The entropy decoding unit 301 may decode entropy coded video data, and from the entropy decoded video data, the motion compensation unit 302 provides a motion vector, motion vector precision, reference picture list index and other motion information including motion information. information can be determined. Motion compensation unit 302 may determine this information, for example, by performing AMVP and merge mode.

The motion compensation unit 302 may perform interpolation based on the interpolation filter to generate a motion compensation block. An identifier for an interpolation filter used with sub-pixel precision may be included in the syntax element.

The motion compensation unit 302 may calculate an interpolation value for a sub-integer pixel of a reference block by using an interpolation filter used by the video encoder 20 while encoding the video block. The motion compensation unit 302 may determine an interpolation filter used by the video encoder 200 according to the received syntax information and generate a predictive block by using the interpolation filter.

The motion compensation unit 302 provides the size of blocks used to encode frames and/or slices of the encoded video sequence, partition information that describes how each macro block of the encoded video sequence is partitioned, and in which each partition is encoded. Some syntax information can be used to determine the method, the mode that indicates how each partition is encoded, one or more reference frames (and list of reference frames) for each inter-encoded block, and other information to decode the encoded video sequence. have.

The intra prediction unit 303 may form a prediction block from a spatially adjacent block using, for example, an intra prediction mode received in a bitstream. The inverse quantization unit 303 inverse quantizes, eg, de-quantizes, the quantized video block coefficient provided in the bitstream and decoded in the entropy decoding unit 301 . An inverse transform unit 303 applies an inverse transform.

A reconstruction unit 306 may sum the residual block and the corresponding prediction block generated by the motion compensation unit 202 or the intra prediction unit 303 to form a decoded block. If desired, the decoded block may be filtered to remove blocking artifacts by applying a deblocking filter. The decoded video block is then stored in a buffer 307, which provides a reference block for subsequent motion compensation.

11 is a flowchart representation of a video processing method according to the present technology. The method 1100 includes, at operation 1110 , performing a transform between a first block of video and a bitstream representation of the video. The bitstream representation conforms to a format rule that specifies that the applicability of the decoder-side motion vector refinement coding tool and the bidirectional optical flow coding tool to a video picture is indicated separately in the bitstream representation.

13 is a flowchart representation of a video processing method 1300 according to the present technology. The method 1300 includes, in operation 1310 , use of a coding tool based on a condition associated with a dimension of a portion of one of multiple reference pictures or a current picture to transform between a current picture of the video and a bitstream representation of the video. including the step of determining Method 1300 includes, at operation 1320 , performing a transform based on the determining.

In some embodiments, usage includes whether a coding tool is activated for the current picture. In some embodiments, the part of the picture includes a conformance window in which samples can be disposed of externally when outputting video, a scaling window in which samples are subjected to a resampling operation, or the entire picture. In some embodiments, the coding tool includes a decoder-side motion vector refinement coding tool, a bidirectional optical flow coding tool, predictive refinement using an optical flow (PROF) coding tool, or a half-pixel precision interpolation filter for motion compensation or motion compensation. do. In some embodiments, the coding tool is a temporal motion vector predictive coding tool, a multiple transform set coding tool, a cross component adaptive loop filtering coding tool, a geometric partition coding tool, a mixing process of a coding tool that divides a block into multiple partitions, the current A coding tool that requires information stored in a picture different from a picture, a coding tool that generates pairwise merge candidates, double prediction using coding unit level weights, a weighted prediction coding tool, an affine prediction coding tool, or an adaptive motion vector resolution coding tool further includes

In some embodiments, the coding tool is deactivated when a condition specifying a dimension in a part of at least one of the multiple reference pictures is different from a dimension of the current picture. In some embodiments, some dimensions are modified for the determining step. In some embodiments, use of the coding tool is based on at least one of (1) the width of the picture minus one or more horizontal offsets, or (2) the height of the picture minus one or more vertical offsets. In some embodiments, the one or more horizontal offsets include a left offset relative to the scaling window. In some embodiments, the one or more vertical offsets include a top offset relative to the scaling window. In some embodiments, the one or more horizontal offsets include a right offset and a left offset relative to the scaling window. In some embodiments, the one or more vertical offsets include a bottom offset and a top offset relative to the scaling window. In some embodiments, the one or more horizontal offsets include a value based on scaling the sum of the right and left offsets relative to the scaling window. In some embodiments, the one or more vertical offsets include a value based on scaling a sum of the bottom offset and the top offset for the scaling window.

In some embodiments, the coding tool is deactivated when it is satisfied that the condition specifying the dimension of at least two parts of the multiple reference pictures is different. In some embodiments, the first pairwise merging candidate is marked as unavailable when dimensions of at least two portions of multiple reference pictures used to derive the first pairwise merging candidate for one or two reference picture lists are different. . In some embodiments, a syntax element indicating the use of a coding tool is conditionally signaled in the bitstream representation based on some dimension. In some embodiments, a syntax element indicating the use of a coding tool is omitted from the bitstream representation.

In some embodiments, a syntax element indicating use of a coding tool is conditionally included in the bitstream representation further based on whether a reference picture resampling (RPR) process is activated. In some embodiments, the syntax element includes one of amvr_precision_idx, sym_mvd_flag, or mmvd_merge_flag. In some embodiments, the transform upon use of the coding tool is modified based on some dimension. In some embodiments, the transform comprises deriving a motion vector difference for the reference picture list in a symmetric motion vector difference process, wherein the derivation is based on a difference in dimensions of some of at least two of the multiple reference pictures. In some embodiments, the transform comprises deriving a pairwise merging candidate, and deriving comprises applying a weighted average based on a difference in dimensions of at least two portions of the multiple reference pictures.

14 is a flowchart representation of a video processing method 1300 in accordance with the present technology. The method 1400 includes, at an operation 1410 , performing a transform between a block of video and a bitstream representation of the video. Adaptive Motion Vector Resolution (AMVR) with 1/2-pel motion vector precision is enabled for the block because the reference picture resampling process is applied to the block during transformation.

In some embodiments, different interpolation filters are used for blocks with other precision than 1/2-pel precision. In some embodiments, a condition associated with a dimension of a portion of a reference picture is indicated by a flag associated with the reference picture. In some embodiments, the coding tool is deactivated when the flag indicates that at least one reference picture in the reference picture list is to be scaled. In some embodiments, the flag includes RefPicIsScaled[ 0 ][ refIdxL0 ], where refIdxL0 is an index into the first reference picture list. In some embodiments, the flag comprises RefPicIsScaled[ 0 ][ refIdxL1 ], where refIdxL1 is an index to the second first reference picture list. In some embodiments, the flag is determined during the reference picture list construction process.

15 is a flowchart representation of a video processing method 1500 according to the present technology. The method 1500 includes, in an operation 1510 , a bidirectional optical flow (BDOF) coding tool or decoder-side motion vector refinement ( DMVR) determining the sum of absolute differences used in the coding tool. Method 1500 includes, at operation 1520 , performing a transformation based on the determining.

In some embodiments, the sum of absolute differences is shifted based on a function of bit depth before being compared to a threshold for a BDOF coding tool or a DMVR coding tool. In some embodiments, the sum of absolute differences is compared to a threshold that is modified based on a function of bit depth.

In some embodiments, transforming comprises encoding the video into a bitstream representation. In some embodiments, transforming comprises decoding the bitstream representation into video.

Some embodiments of the disclosed techniques include making a decision or making a decision to activate a video processing tool or mode. For example, when a video processing tool or mode is activated, the encoder uses or implements the tool or mode in video block processing, but does not necessarily modify the resulting bitstream according to the use of the tool or mode. That is, converting from video blocks to bitstream representations of video uses a video processing tool or mode when activated by a judgment or decision. In another example, when a video processing tool or mode is activated, the decoder processes the bitstream knowing that the bitstream has been modified according to the video processing tool or mode. That is, the conversion from a bitstream representation of a video to a video block is performed using a judgment or a video processing tool or mode activated according to the decision.

Some embodiments of the disclosed techniques include making a decision or making a decision to disable a video processing tool or mode. For example, if a video processing tool or mode is deactivated, the encoder does not use the tool or mode to convert a video block to a video block. In another example, when a video processing tool or mode is deactivated, the decoder will process the bitstream with the knowledge that the bitstream has not been modified using the video processing tool or mode activated based on the determination or determination.

The teachings and other solutions, examples, embodiments, modules and functional works described herein may be implemented in digital electronic circuitry, or computer software, firmware, or hardware, including this document and structural equivalents thereof, or combinations of one or more thereof. can be implemented as The disclosed and other embodiments may be implemented as one or more computer program products, for example, encoding and executing one or more modules of computer program instructions on a computer readable medium or controlling the operation of a data processing device. The computer-readable medium can be a machine-readable storage device, a machine-readable storage substrate, a memory device, a composition of matter that affects a machine-readable radio signal, or a combination of one or more. The term "data processing apparatus" includes all apparatus, apparatus and computers for processing data, including, for example, programmable processors, computers, or multiple processors or computers. A device may include, in addition to hardware, code that creates an execution environment for a corresponding computer program, eg, code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more thereof. A propagated signal is an artificially generated signal, eg, a mechanically generated electrical, optical or electromagnetic signal, which is generated to encode information for transmission to a suitable receiver device.

A computer program (also referred to as a program, software, software application, script or code) may be written in any form of programming language, including compiled language, and may contain modules, components, subroutines or It can be distributed in any form as other units. A computer program does not necessarily correspond to a file in a file system. A program may contain other programs or data (e.g., one or more scripts stored in a markup language document), a single file or several coordinated files dedicated to the corresponding program (e.g., one or more modules, subprograms, or portions of code). can be saved to a file that stores . A computer program may be distributed for execution on one computer or on multiple computers located at one site or distributed over multiple sites and interconnected by a communications network.

The processes and logic flows described in this document may be performed by one or more programmable processors on the one or more programmable processors to operate on input data and generate outputs to perform functions. Processes and logic flows may also be performed, and devices may be implemented with special purpose logic circuits, for example, field programmable gate arrays (FPGAs) or application specific integrated circuits (ASICs).

Processors suitable for the execution of computer programs include, for example, general and special purpose microprocessors and one or more processors of digital computers of all kinds. Typically, a processor will receive instructions and data from either read-only memory or random-access memory, or both. An essential element of a computer is a processor for executing one or more memory devices for storing instructions and data. In general, a computer also receives data from, transmits data to, or includes both, or operatively connects one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. do. However, the computer does not need such a device. Computer readable media suitable for storing computer program instructions and data include semiconductor memory devices such as EPROM, EEPROM and flash memory devices, magnetic disks such as internal hard disks or removable disks; magneto optical disc; and all forms of non-volatile memory, media and memory devices, including CD ROM and DVD-ROM disks. The processor and memory may be supplemented or integrated by special purpose logic circuitry.

Although this patent document contains many details, it should not be construed as a limitation on the scope of any subject matter or what may be claimed, but rather as descriptions of features that may be specific to particular implementations of particular technologies. is not Certain features described in this patent document may be implemented in the context of separate embodiments and in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments, either individually or in any suitable sub-combination. Moreover, as before, features may be described and even initially claimed as acting in a particular combination, however, one or more features from a claimed combination may in some cases be excluded from the combination, and the claimed combination may be a sub-combination. Or it may relate to the modification of the sub-combination.

Likewise, while acts are depicted in the figures in a particular order, they should not be construed as requiring that these acts be performed in the particular order indicated or sequential order, or that all illustrated acts are performed, to achieve desirable results. . Moreover, in the embodiments described in this patent document, separation of various system components should not be construed as requiring such separation in all embodiments.

Only a few implementations and examples are described, and other implementations, improvements, and variations may be made in accordance with the teachings and shown in this patent document.

Claims (38)

A video processing method comprising:
determining use of a coding tool based on a condition associated with dimensions of multiple reference pictures or a portion of one of the current pictures for transformation between a current picture of the video and a bitstream representation of the video; and
performing the transformation according to the determination;
Way.
According to claim 1,
The use includes whether the coding tool is activated for the current picture.
Way.
3. The method of claim 1 or 2,
A portion of the picture includes a fitness window that can dispose of samples externally when outputting the video, or a scaling window in which samples must be resampled, or the entire picture
Way.
4. The method according to any one of claims 1 to 3,
The coding tool comprises a decoder-side motion vector refinement coding tool, a bidirectional optical flow coding tool, predictive refinement of an optical flow (PROF) coding tool, or a half-pixel precision interpolation filter for motion compensation.
Way.
5. The method of claim 4,
The coding tool is a temporal motion vector predictive coding tool, a multiple transform set coding tool, a cross component adaptive loop filtering coding tool, a geometric partition coding tool, a mixing process of a coding tool that divides a block into multiple partitions, a picture different from the current picture Further comprising a coding tool that requires information stored in
Way.
6. The method according to any one of claims 1 to 5,
The coding tool is deactivated when a condition for specifying a dimension in at least one part of the multiple reference pictures is different from the dimension of the current picture
Way.
7. The method according to any one of claims 1 to 6,
The dimension of the part is modified for the step of determining
Way.
8. The method according to any one of claims 1 to 7,
wherein use of the coding tool is based on at least one of (1) the width of the picture minus one or more horizontal offsets, or (2) the height of the picture minus one or more vertical offsets.
Way.
9. The method of claim 8,
wherein the one or more horizontal offsets include a left offset relative to the scaling window.
Way.
9. The method of claim 8,
wherein the one or more vertical offsets include a top offset relative to a scaling window.
Way.
9. The method of claim 8,
wherein the one or more horizontal offsets include a right offset and a left offset relative to a scaling window.
Way.
9. The method of claim 8,
wherein the one or more vertical offsets include a bottom offset and a top offset relative to the scaling window.
Way.
9. The method of claim 8,
wherein the one or more horizontal offsets include a value based on scaling a sum of a right offset and a left offset relative to a scaling window.
Way.
9. The method of claim 8,
wherein the one or more vertical offsets include a value based on scaling a sum of the bottom offset and the top offset for a scaling window.
Way.
6. The method according to any one of claims 1 to 5,
The coding tool is deactivated when it is satisfied that the conditions for specifying the dimensions of at least two parts of the multiple reference pictures are different
Way.
6. The method according to any one of claims 1 to 5,
The first pairwise merge candidate is marked as unavailable when dimensions of at least two parts of the multiple reference pictures used to derive the first pairwise merge candidate for one or two reference picture lists are different.
Way.
17. The method according to any one of claims 1 to 16,
A syntax element indicating use of the coding tool is conditionally signaled in the bitstream representation based on the dimension of the part.
Way.
18. The method of claim 17,
The syntax element indicating use of the coding tool is omitted from the bitstream representation.
Way.
18. The method of claim 17,
wherein the syntax element indicating use of the coding tool is conditionally included in the bitstream representation further based on whether a reference picture resampling (RPR) process is activated.
Way.
19. The method of claim 18,
The syntax element includes one of amvr_precision_idx, sym_mvd_flag, or mmvd_merge_flag
Way.
21. The method according to any one of claims 1 to 20,
The transform according to the use of the coding tool is modified based on the dimension of the part.
Way.
22. The method of claim 21,
The transformation includes deriving a motion vector difference for a reference picture list in a symmetric motion vector difference process, wherein the deriving step is based on a difference in dimensions of at least two portions of the multiple reference pictures
Way.
22. The method of claim 21,
The transformation includes deriving a pairwise merge candidate, and the deriving includes applying a weighted average based on a difference in dimensions of at least two parts of the multiple reference pictures.
Way.
A video processing method comprising:
performing a conversion between a video and a bitstream representation of the video;
Adaptive Motion Vector Resolution (AMVR) of 1/2-pel motion vector precision is activated for the block because the reference picture resampling process is applicable to the block during the transformation.
Way.
25. The method of claim 24,
If different interpolation filters are used for blocks with different precision than 1/2-pel precision.
Way.
26. The method according to any one of claims 1 to 25,
A condition associated with the dimension of a portion of the reference picture is indicated by a flag associated with the reference picture.
Way.
27. The method of claim 26,
the coding tool is deactivated when the flag indicates that at least one reference picture in the reference picture list is to be scaled
Way.
28. The method of claim 27,
The flag includes RefPicIsScaled[0][refIdxL0], where refIdxL0 is an index to the first reference picture list.
Way.
28. The method of claim 27,
The flag includes RefPicIsScaled[0][refIdxL1], where refIdxL1 is an index to the second first reference picture list.
Way.
30. The method according to any one of claims 26 to 29,
The flag is determined in the reference picture list construction process
Way.
A video processing method comprising:
Sum of absolute differences used in a bidirectional optical flow (BDOF) coding tool or decoder-side motion vector refinement (DMVR) coding tool in a manner based on the bit depth of the block, for conversion between a block of video and a bitstream representation of said video determining; and
performing the transformation according to the determining
Way.
32. The method of claim 31,
The sum of the absolute differences is shifted based on a function of the bit depth before being compared to a threshold for the BDOF coding tool or the DMVR coding tool.
Way.
32. The method of claim 31,
wherein the sum of the absolute differences is compared with a threshold that is modified based on a function of the bit depth.
Way.
34. The method according to any one of claims 1 to 33,
wherein the transform comprises encoding the video into the bitstream representation.
Way.
34. The method according to any one of claims 1 to 33,
wherein the transform comprises decoding the bitstream representation into video
Way.
36. A video processing apparatus comprising a processor configured to implement the method according to any one of claims 1 to 35.
A computer-readable medium having a code stored therein, comprising:
36. A computer readable medium having stored thereon the code, when executed by a processor, causing the processor to implement the method of any one of claims 1-35.
36. A computer readable medium storing a bitstream representation generated according to any one of claims 1 to 35.

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